FINAL150

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Assume a is 13 and b is 10; what prints? string s{"feed the fish"}; cout << s.substr(a, b) << endl;

[2329] What is the value of r("hello")? string r(const string& s) { if (s.size() > 1) { string t = s[0] == s[1] ? "" : "*"; return t + s[0] + r(s.substr(1)); } return s; } "h*e*ll*o*" Stack overflow "h*e*ll*o" "hel*lo" "**h***el**lo"

"**h***el**lo"

What value is stored in a after this runs? string s{"ABCDEFGHIJKLM"}; auto a = s.substr(1, 4);

"BCDE"

[1713] What happens here? char s1[] = "CS150", s2[10]; strcpy(s2, s1); s2[0] = 'X'; cout << s1 << endl; "XS150" "CS150" Does not compile Crashes when run. Undefined behavior

"CS150"

[1710] What happens here? char s[50] = "CS150"; strcat(s, "CS50"); cout << s << endl; Crashes when run Undefined behavior "CS50" "CS500" "CS150CS50"

"CS150CS50"

[1708] What happens here? char s[] = "CS150"; strcpy(s, "CS50"); cout << s << endl; Crashes when run Undefined behavior "CS50" "CS500" "CS150CS50"

"CS50"

What is the output of the following? bool token1 = true; while (token1) { for (int i = 0; i < 5; i++) { cout << "Hello there" << endl; } token1 = false; }

"Hello there" will be displayed 5 times.

What is the output of the following? bool val1 = true; bool val2 = false; while (val1) { if (val1) { cout << "Hello" << endl; } val1 = val2; }

"Hello" will be displayed only once.

What is the output of the following? int i = 1; while (i <= 10) { cout << "Inside the while loop" << endl; i = i * 11; }

"Inside the while loop" will be displayed only once.

[1711] What happens here? char s1[] = "CS150"; char *s2 = s1; s2[0] = 'X'; cout << s1 << endl; "XS150" "CS150" Crashes when run Does not compile Undefined behavior

"XS150"

[2323] What is the value of r("axxbxx")? string r(const string& s) { auto front = s.substr(0, 1); if (front.empty()) return ""; return (front == "x" ? "" : front) + r(s.substr(1)); } "a b " "xxxx" "ax bx " "ab" Stack overflow

"ab"

What value is stored in a after this runs? string s{"abcdefg"}; auto a = s.substr(3);

"defg"

Assume a is 9 and b is 10; what prints? string s{"feed the fish"}; cout << s.substr(a, b) << endl;

"fish"

[2328] What is the value of r("hello")? string r(const string& s) { if (s.size() > 1) { string t = s[0] == s[1] ? "" : "*"; return s[0] + t + r(s.substr(1)); } return s; } "h*e*ll*o" "hel*lo" "*h*e*ll*o" Stack overflow "h*e*ll*o*"

"h**e***ll**o"

[2326] What is the value of r("hello")? string r(const string& s) { if (s.size() < 2) return s; return s.substr(0, 1) + "*" + r(s.substr(1)); } "*h*e*l*l*o" "h*e*l*l*o*" "h*e*l*l*o" Stack overflow "*h*e*l*lo"

"h*e*l*l*o"

[2327] What is the value of r("hello")? string r(const string& s) { if (s.size() > 1) { string t = s[0] == s[1] ? "*" : ""; return s[0] + t + r(s.substr(1)); } return s; } "h*e*ll*o*" Stack overflow "h*e*ll*o" "*h*e*ll*o" "hel*lo"

"hel*lo"

Compare C++ and Java string. Which of these are true?

"hello" is a string object in Java, but not in C++ String s; produces the null string in Java, while string s; produces the empty string in C++. String is capitalized in Java, lowercase in C++ Assuming str is a string, str + "b" is legal in both Java and C++

Assume a is 5 and b is 3; what prints? string s{"feed the fish"}; cout << s.substr(a, b) << endl;

"the"

[2324] What is the value of r("axxbxx")? string r(const string& s) { auto front = s.substr(0, 1); if (front.empty()) return ""; return (front == "x" ? front : "") + r(s.substr(1)); } "ax bx " "a b " Stack overflow "xxxx" "ab"

"xxxx"

What preprocessor directive is not used when you wish to create blocks of code that are only compiled under certain circumstances?

#define #ifdef #ifndef #if --> All of these may be used

Needed to use the C++ string type

#include <string> (choice F)

[2437] What prints? class Employee { public: Employee() = default; Employee(const string& n, double s) : name(n), salary(s) {} void setName(const string& n) { name = n; } void setSalary(double s) { salary = s; } string getName() const { return name; } double getSalary() const { return salary; } private: string name; double salary = 0; }; class Manager : public Employee { public: Manager() = default; Manager(double b) { bonus = b; } Manager(const string& n, double s, double b) : Employee(n, s), bonus(b) {} void setBonus(double b) { bonus = b; } void print() const; private: double bonus; }; void Manager::print() const { cout << getName() << " $ " << getSalary() << "; Bonus: " << bonus << endl; } int main() { Manager m1; Manager m2(1000); Manager m3("Peter", 30000, 1000); m2.print(); } Peter $ 30000; Bonus: 1000 $ 30000; Bonus: 1000 Peter $ 0; Bonus: 1000 $ 0; Bonus: 1000

$ 0; Bonus: 1000

Which of these are targets? EXE=digit-tester OBJS=client.o digits.o $(EXE): $(OBJS) $(CXX) $(CXXFLAGS) $(OBJS) -o $(EXE)

$(EXE) digit-tester

[1418] What is the equivalent array notation? int dates[10]; cout << (dates + 2) << endl; dates[2] + 2 &dates[2] dates[0] + 2 dates[2] dates[0] + 4

&dates[2]

Assume c is a char variable. What value s stored in the variable a? string s{"guten tag"}; auto len = s.size(); auto a = s.front(); s.at(len) = a; s[len] = c;

'g'

In Line 2, what is the explicit argument? string s{"happy"}; auto pos = s.find('y');

'y'

[1415] Which returns the last pixel on the first row of this image? Pixel *p; // address of pixel data int w, h; // width and height of image *p + w - 1 None of these are correct *(p + w) - 1 p + w - 1 *(p + w - 1)

*(p + w - 1)

[1423] What is the equivalent address-offset notation? int a[] = {1, 2, 3, 4, 5, 6, 7}; int *p = a; cout << a[1] * 2 << endl; None of these **p + 1 ** 2 p + 1 * 2 (**p + 1) ** 2 **(p + 1) ** 2

**(p + 1) ** 2

[1350] Here is the pseudocode for the greenScreen() function in H12. What single statement sets the red, green and blue components to 0? Let p point the beginning of the image Set end to point just past the end While p != end If *(p + 3) is 0 (transparent) Clear all of the fields Increment p by 4

**(p) = ***(p + 1) = **(p + 2) = 0;

[1724] Which while condition makes this function correct? int stringComp(const char **s1, const char ** s2) { while (. . .) { s1++; s2++; } return **s1 - **s2 } **s1 != **s2 **s1 == **s2 **s1 && **s2 **s1 == ***s2 || ***s1 || **s2 **s1 == ***s2 && ***s1 && **s2

**s1 == ***s2 && ***s1 && **s2

[1412] Which assigns a value to the first position in letters? char letters[26]; *letters = 'a'; *letters = "a"; *letters[0] = 'a'; *(letters + 1) = 'a'; *letters + 1 = 'b';

*letters = 'a';

[1327] Which expression obtains the value that p points to? int x(100); int *p = &x;

[1324] What is true about this code? int n{500}; int *p = &n;

*p is the value of n

[1310] The variable buf is a pointer to a region of memory storing contiguous int values. (This is similar to your homework, where you had a region of memory storing unsigned char values) The four lines shown here are legal. Which operation is illegal? int *p1 = buf; const int *p2 = buf; int * const p3 = buf; const int * p4 const = buf; p2++; *p1 = 3; *p3 = 5; p1++; *p2 = 7

*p2 = 7;

[1312] The variable buf is a pointer to a region of memory storing contiguous int values. (This is similar to your homework, where you had a region of memory storing unsigned char values.) The four lines shown here are legal. Which operation is legal? int *p1 = buf; const int *p2 = buf; int * const p3 = buf; const int * p4 const = buf;

*p3 = 5;

[2222] The Point class represents x,y coordinates in a Cartesian plane. Which line of code appears completes this operator? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } Point& operator++() { Point temp(*this); . . . return ________________; } }; *this temp Does not compile; cannot change data members of object; no mutators Does not compile; must be a non-member function Does not compile; changes arity of operator; should be unary, not empty

*this

Which line runs a.out getting its input from in.txt and sending its output to the file out.txt, and its errors to the file err.txt?

./a.out < in.txt > out.txt 2> err.txt

Which line runs a.out getting its input from in.txt and appending its output to the file out.txt?

./a.out > in.txt >> out.txt

Which line runs a.out getting its input from in.txt and sending its output to the new file out.txt?

./a.out > out.txt < in.txt

Which line runs the dd program and sends its errors to file named z.data?

./dd 2> z.data

Which line runs the dmm program and adds its output to a file named x.data?

./dmm >> x.data

Which line runs the dom program and sends both output and errors to file named v.data?

./dom > v.data 2>&1

Which line runs the dwk program and gets its input from a file named y.data?

./dwk < y.data

Which line runs the prt program and stores its output in a new file named x.data?

./prt > x.data

Assume that the user enters: Steve 3.5 68 What value is stored in gpa? string name; int age; double gpa; cout << "Enter your name, age and gpa: "; cin >> name >> age >> gpa;

What prints? int main() { cout << fixed << 2.0 / 3.0 << endl; }

.666667

Which line in the function "skeleton" below contains an error? #include "digits.h" // 1. int firstDigit(int n); // 2. { // 3. return 0; // 4. } // 5.

// 2.

Which line in the function "skeleton" below contains an error? #include "borgia.h" // 1. void primoTiara(int n) // 2. { // 3. return 0; // 4. } // 5.

// 4.

[1405] What is stored in the last element of nums? int nums[3] = {1, 2}; Undefined value 2 Syntax error in array declaration 0 1

What is the output of the following? int i = 0; while (i != 11) { cout << i << " "; i = i + 2; }

0 2 4 6 8 10 12 14 .... (infinite loop)

What is the output of the following? int i = 0; while (i != 9) { cout << i << " "; i = i + 2; }

0 2 4 6 8 10 12 14 .... (infinite loop)

How many variables appear in the following code segment? int n = 4; int& r1 = n; auto& r2 = r1; r1 = 3; r2 = 5; cout << n << endl;

What is the size of data, after this runs? vector<int> data; data.push_back(3);

What prints here? auto a = 1; switch (a) { case 1: cout << "1"; break; case 2: cout << "2"; break; default: cout << "3"; } cout << endl;

What prints? vector<int> v{1, 2, 3, 4, 5}; v.pop_back(); cout << v.front() << endl;

What prints? void f(vector<int> v) { v.at(0) = 42; } int main() { vector<int> x{1, 2, 3}; f(x); cout << x.at(0) << endl; }

Which line prints 3? int main() { vector<int> v{1, 2, 3}; auto size = v.size(); cout << v.back() << endl; // 1. cout << v.front() << endl; // 2. cout << v.at(0) << endl; // 3. cout << v.at(size) << endl; // 4. cout << v.pop_back() << endl; // 5. }

[1343] Examine the following code. What is stored in c after it runs. int f(int * p, int x) { **p = x ** 2; return x / 2; } . . . int a = 3, b, c; c = f(&b, a);

[1530] What is printed? int mystery(const int a[], size_t n) { int x = 0; for (size_t i = 0; i < n; i++) if (a[i] < a[x]) x = i; return x; } int main() { int a[] = {4, 2, 5, 2, 5, 4}; cout << mystery(a, 6) << endl; } None of these 2 0 1 3

[1832] What prints? int a[5][3] = { { 1, 2, 3}, { 4, 5, 6}, { 7, 8, 9}, {10, 11, 12}, {13, 14, 15} }; int *p = &a[0][0]; cout << *p << endl; 4 Illegal; will not compile 1 An address Undefined (out of bounds)

This code is legal, compiles and is well defined. Which line(s) contain initialization? int a = 5; // 1 a == 5; // 2 int b = 6; // 3 a ={b}; // 4 auto c = a == b; // 5

1 3 5

What is the output of the following? int i = 1; while (i < 20) { cout << i << " "; i = i + 2; if (i == 15) { i = 19; } }

1 3 5 7 9 11 13 19

What is the output of the following? int i = 1; while (i < 10) { cout << i << " "; i = i + 2; if (i == 5) { i = 9; } }

1 3 9

What is the output of the following? int i = 1; while (i != 9) { cout << i << " "; i++; if (i = 9) { cout << "End"; } }

1 End

[1721] Which lines create the C-string "hello"? 1. char s[10] = "hello"; 2. char s[10] = {'h','e','l','l','o'}; 3. char s[] = {'h','e','l','l','o','0'}; 4. char s[5] = "hello"; 5. char s[] = "hello"; 1, 2, 3, 5 1, 2, 5 All of them 1, 3 1, 5

1, 2, 5

[1722] Which lines contains exactly two characters? 1. "\n" 2. '\n' 3. "n" 4. "/n" 5. 'n' 1, 3, 5 1, 2, 4 All of them 1, 3, 4 1, 3

1, 3

How many times is this loop entered? (That is, how many times is i printed?) for (int i = 0; i < 10; i++) cout << i; cout << endl;

How many times is this loop entered? (That is, how many times is i printed?) for (int i = 1; i <= 10; i++) cout << i; cout << endl;

[1331] What is printed when you run this code? int num = 0; int *ptr = &num; num = 5; *ptr += 5; cout << num << " " << *ptr << endl;

10 10

[2026] What prints here? class Car { double speed; public: Car(); Car(double s); double get() const; }; Car::Car() { speed = 10; } Car::Car(double s) { speed = s; } double Car::get() const { return speed; } int main() { Car c1, c2(5); cout << c1.get() << c2.get() << endl; } Does not compile; c1 is not an object 15 Undefined; c1 not initialized 05 105

105

How many times is this loop entered? (That is, how many times is i printed?) for (int i = 0; i <= 10; i++) cout << i; cout << endl;

[1821] What prints? int cnt = 0, a[4][5]; for (int i = 0; i < 5; i++) for (int j = 0; j < 4; j++) a[j][i] = cnt++; cout << a[3][2] << endl; 14 11 9 8 19

[1822] What prints? int cnt = 0, a[4][5]; for (int i = 0; i < 5; i++) for (int j = 0; j < 4; j++) a[j][i] = cnt++; cout << a[3][2] << endl; 11 8 9 14

[1834] What prints? int a[5][3] = { { 1, 2, 3}, { 4, 5, 6}, { 7, 8, 9}, {10, 11, 12}, {13, 14, 15} }; int *p = &a[0][0]; cout << p[10] << endl; Illegal; will not compile An address 10 11 Undefined (out of bounds)

What prints here? auto a = 1; switch (a) { case 1: cout << "1"; case 2: cout << "2"; } cout << endl;

[1835] What prints? int a[5][3] = { { 1, 2, 3}, { 4, 5, 6}, { 7, 8, 9}, {10, 11, 12}, {13, 14, 15} }; int *p = &a[0][0]; cout << (p + 5 * 2)[1] << endl; 13 12 11 Undefined (out of bounds) Illegal; will not compile

[2310] What is the value of mystery(5)? int mystery(int n) { if (n > 0) return 3 - n % 2 + mystery(n-1); return 0; } 7 12 5 10 15

[1424] What prints? int a[] = {1, 3, 5, 7, 9}; int *p = a; cout << *p++; cout << *p << endl; 13 None of these 33 22 12

[1820] What prints? int cnt = 0, a[4][5]; for (int i = 0; i < 5; i++) for (int j = 0; j < 4; j++) a[j][i] = cnt++; cout << a[2][3] << endl; 19 14 11 9 8

How many times will this display "So far so good"? int i = 0; while (i != 15) { cout << "So far so good" << endl; i++; }

15 times

Match each item with the correct statement below. unsigned long signed int unsigned long long unsigned int signed long signed long long

15UL 12 15ULL 15U 3L 15LL

[1804] What prints? Assume 4 bytes per int. int a[][2] = {{0},{0}}; cout << sizeof(a) << endl; 4 12 16 8 Illegal declaration. Does not compile.

[1805] What prints? Assume 4 bytes per int. int a[][2] = {1, 2, 3}; cout << sizeof(a) << endl; 8 12 4 16 Illegal declaration. Does not compile.

Assume that the input is 4 4 3 2 5. What will print? int i = 1; int n; cin >> n; do { i++; cin >> n; } while (n % 2); cout << i << endl;

What prints here? auto a = 2; switch (a) { case 1: cout << "1"; break; case 2: cout << "2"; break; default: cout << "3"; } cout << endl;

Which line or lines are illegal? /*1*/ int a, b; /*2*/ a = 3; int main() { /*3*/ b = 4; /*4*/ cout << a << ", " << b << endl ; }

Which line represents the necessary bounds in this loop? 1. string s("Hello CS 150"); 2. while (s.size()) 3. { 4. if (s.at(0) == 'C') break; 5. s = s.substr(1); 6. } 7. cout << s << endl;

[1510] Below is a cumulative algorithm using an array and an iterator-based loop. What is printed? (Assume all includes have been added, etc.) double average(const int *beg, const int *end) { double sum = 0; size_t count = end - beg; while (beg != end) sum += *beg++; return sum / count; } int main() { int a[] = {2, 4, 6, 8}; cout << average(a, a + 1) << endl; } Does not compile 3 2 5 4

[1516] What is printed here? (Assume all includes have been added. Assume 4-bytes per int, 8 bytes per pointer.) size_t len(const int a[]) { return sizeof(a) / sizeof(a[0]); } int main() { int a[] = {2, 4, 6, 8}; cout << len(a) << endl; } 2 Does not compile 1 4

[1529] What is printed? int mystery(const int a[], size_t n) { int x = 0; for (size_t i = 0; i < n; i++) if (a[i] > a[x]) x = i; return x; } int main() { int a[] = {4, 2, 5, 2, 5, 4}; cout << mystery(a, 6) << endl; } 5 None of these 0 2 4

[1823] How many rows are in this array? int a[2][3]; 6 3 5 4 2

[1826] How many (int[]) elements are in this array? int a[2][3]; 5 3 2 4 6

[2316] What is the value of r(81238)? int r(int n) { if (!n) return 0; return (n % 10 == 8) + (n % 100 == 88) + r(n / 10); } Does not compile 2 Stack overflow 5 3

This code is legal, compiles and is well defined. Which line(s) contain comparison? int a = 5; // 1 a == 5; // 2 int b = 6; // 3 a ={b}; // 4 auto c = a == b; // 5

2 5

Which lines have an identical effect? int main() { vector<int> v{1, 2, 3}; auto size = v.size(); cout << v.back() << endl; // 1. cout << v.front() << endl; // 2. cout << v.at(0) << endl; // 3. cout << v.at(size) << endl; // 4. cout << v.pop_back() << endl; // 5. }

2 and 3

[1330] What is printed when you run this code? int n{}; int *p = &n; *p = 10; n = 20; cout << *p << endl;

[1838] What prints? int x = 0; int a[2][3] = {{1, 2, 3}, {4, 5, 6}}; for (const auto& r : a) for (const auto& c : r) x += c; cout << x << endl; 21 Undefined (out of bounds) 15 6 Illegal; will not compile

[2309] What is the value of r(6)? int r(int n) { if (n > 0) return n + r(n - 1); return n; } 15 6 10 24 21

[1426] What prints? int a[] = {1, 3, 5, 7, 9}; int *p = a; cout << ++*p; cout << *p << endl; 13 12 None of these 22 33

What is the output of the following? string s = "12345"; int i = 1; while (i < 5) { cout << s.substr (i, 1); i++; }

2345

[2308] What is the value of mystery(12)? int mystery(int n) { if (!n) return 0; return 2 + mystery(n-1); } 18 24 36 12

What is printed when this runs? int sum = 22; sum +=2; cout << sum++; // sum = sum + 4 cout << sum << endl;

2425

[2318] What is the value of r(3, 3)? int r(int n, int m) { if (m) return n * r(n, m - 1); return 1; } 12 27 Stack overflow 9 3

Assume that the user enters: Steve 3.5 68 What value is stored in age? string name; int age; double gpa; cout << "Enter your name, age and gpa: "; cin >> name >> age >> gpa;

What prints here? auto a = '1'; switch (a) { case 1: cout << "1"; break; case 2: cout << "2"; break; default: cout << "3"; } cout << endl;

What value is stored in a after this runs? string s{"ABCDEFD"}; auto a = s.find('D');

[1345] Examine the following code. What is stored in a after it runs. int f(int * p, int x) { **p = x ** 2; return x / 2; } . . . int a = 3, b, c; c = f(&b, a);

[1511] Below is a cumulative algorithm using an array and an iterator-based loop. What is printed? (Assume all includes have been added, etc.) double average(const int *beg, const int *end) { double sum = 0; size_t count = end - beg; while (beg != end) sum += *beg++; return sum / count; } int main() { int a[] = {2, 4, 6, 8}; cout << average(a, a + 2) << endl; } Does not compile 5 3 4 2

[1519] What is printed here? (Assume all includes have been added. Assume 4-bytes per int, 8 bytes per pointer.) size_t len(const int* a, const int* b) { return b - a; } int main() { int a[] = {2, 4, 6, 8}; cout << len(a, a + 3) << endl; } 2 3 4 Does not compile

[1527] What is printed? int mystery(const int a[], size_t n) { int x = n - 1; while (n > 0) { n--; if (a[n] < a[x]) x = n; } return x; } int main() { int a[] = {4, 2, 5, 2, 5, 4}; cout << mystery(a, 6) << endl; } 1 4 None of these 3 2

[1824] How many columns are in this array? int a[2][3]; 3 6 4 5 2

[2312] What is the value of r(12777)? int r(int n) { if (0 == n) return 0; int x = n % 10 == 7; // 0 or 1 return x + r(n / 10); } 5 Does not compile 2 3 Stack overflow

[2314] What is the value of r(74757677)? int r(int n) { if (n) return (n % 10 != 7) + r(n / 10); return 0; } 5 3 Does not compile 8 Stack overflow

[2325] Assume you have the array: int a[] = {1, 11, 3, 11, 11};. What is the value of r(a, 0, 5)? int r(const int a[], size_t i, size_t max) { if (i < max) return (a[i] == 11) + r(a, i + 1); return 0; } 3 5 Stack overflow 1 0

Assume that the user enters: Steve 60 3.5 What value is stored in gpa? string name; int age; double gpa; cout << "Enter your name, age and gpa: "; cin >> name >> age >> gpa;

3.5

[1816] What prints? int a[2][3] = {{3,2,3}}; cout << a[0][0] << a[1][0] << endl; 00 Code does not compile 31 30 33

[1425] What prints? int a[] = {1, 3, 5, 7, 9}; int *p = a; cout << *++p; cout << *p << endl; 33 13 None of these 22 12

[1818] What prints? int a[3][2] = {3,2,3}; cout << a[0][0] << a[1][0] << endl; Code does not compile 31 33 00 30

The file expenses.txt contains the line: Hotel, 3 nights. $ 1,750.25. What prints? ifstream in("expenses.txt"); char c; while (in.get(c)) { if (isdigit(c)) { in.unget(); double n; in >> n; cout << n << 'x'; } }

3x1x750.25x

The file expenses.txt contains the line: Hotel, 3 nights. $ 1,750.25. What prints? ifstream in("expenses.txt"); char c; while (in.get(c)) { if (isdigit(c)) { in.unget(); int n; in >> n; cout << n << 'x'; } }

3x1x750x25x

Assume c is a char variable. Which line throws an error because of range checking? string s{"guten tag"}; // 1 auto len = s.size(); // 2 auto a = s.front(); // 3 s.at(len) = a; // 4 s[len] = c; // 5

Assume that the input is 5 5 4 3 5. What will print? int i = 1; int n; do { cin >> n; i++; } while (n % 2); cout << i << endl;

This code is legal, compiles and is well defined. Which line(s) contain an assignment? int a = 5; // 1 a == 5; // 2 int b = 6; // 3 a ={b}; // 4 auto c = a == b; // 5

What is the output of the following program? int value = 3; value++; cout << value << endl;

What prints? vector<int> v{1, 2, 3, 4, 5}; v.pop_back(); cout << v.back() << endl;

Which line compiles, but crashes when run? int main() { vector<int> v{1, 2, 3}; auto size = v.size(); cout << v.back() << endl; // 1. cout << v.front() << endl; // 2. cout << v.at(0) << endl; // 3. cout << v.at(size) << endl; // 4. cout << v.pop_back() << endl; // 5. }

Which line prints 5? int n = 12; cout << n/3 << endl; // 1 cout << n/7 << endl; // 2 cout << n % 3 << endl; // 3 cout << n % 7 << endl; // 4

Which line represents the intentional bounds in this loop? 1. string s("Hello CS 150"); 2. while (s.size()) 3. { 4. if (s.at(0) == 'C') break; 5. s = s.substr(1); 6. } 7. cout << s << endl;

[1506] Below is a cumulative algorithm using an array and an iterator-based loop. What is printed? (Assume all includes have been added, etc.) double average(const int *beg, const int *end) { double sum = 0; size_t count = end - beg; while (beg != end) sum += *beg++; return sum / count; } int main() { int a[] = {2, 4, 6, 8}; cout << average(begin(a), end(a) - 1) << endl; } Endless loop when run; likely crashes. Does not compile 4 5 6

[1513] Below is a cumulative algorithm using an array and an iterator-based loop. What is printed? (Assume all includes have been added, etc.) double average(const int *beg, const int *end) { double sum = 0; size_t count = end - beg; while (beg != end) sum += *beg++; return sum / count; } int main() { int a[] = {2, 4, 6, 8}; cout << average(a, a + 3) << endl; } 5 Does not compile 4 2 3

[1517] What is printed here? (Assume all includes have been added. Assume 4-bytes per int, 8 bytes per pointer.) int main() { int a[] = {2, 4, 6, 8}; cout << sizeof(a) / sizeof(a[0]) << endl; } Does not compile 4 1 2

[1518] What is printed here? (Assume all includes have been added. Assume 4-bytes per int, 8 bytes per pointer.) size_t len(const int* a, const int* b) { return b - a; } int main() { int a[] = {2, 4, 6, 8}; cout << len(begin(a), end(a)) << endl; } Does not compile 4 2 1

[1528] What is printed? int mystery(const int a[], size_t n) { int x = n - 1; while (n > 0) { n--; if (a[n] > a[x]) x = n; } return x; } int main() { int a[] = {4, 2, 5, 2, 5, 4}; cout << mystery(a, 6) << endl; } None of these 4 3 1 2

[1813] What is the value of a[1][1] after this runs? int cnt = 0, a[2][3]; for (int i = 0; i < 3; i++) for (int j = 0; j < 2; j++) a[j][i] = ++cnt; 6 4 2 3 5

[2315] What is the value of r(8818)? int r(int n) { if (!n) return 0; return (n % 10 == 8) + (n % 100 == 88) + r(n / 10); } Stack overflow 4 Does not compile 3 1

[2319] What is the value of r("xxhixx")? int r(const string& s) { if (s.size()) return (s.at(0) == 'x') + r(s.substr(1)); return 0; } 4 2 3 6 Stack overflow

Which of these lines are legal? [1] int n1 = 4; [2] double n2 = 3.145; [3] unsigned char n3 = 158; [4] int n4 = n2; [5] int& r1 = n1; [6] int& r2 = n2; [7] double& r3 = n1; [8] const int& r4 = n2;

4 5 8

Which lines cause syntax errors? [1] string s{"shiver me timbers"}; [2] auto len = s.size(); [3] s.front() = 'S'; [4] s.back() = "S"; [5] s[len] = 'X'; [6] s.substr(0, 1) = "W"; [7] auto a = s.substr(0, 100); [8] auto b = s.substr(4, 3); [9] auto c = s.substr(len);

4 6

What prints? void f(vector<int>& v) { v.at(0) = 42; } int main() { vector<int> x{1, 2, 3}; f(x); cout << x.at(0) << endl; }

[1934] The member function get() returns the raw pointer that a smart pointer contains. What does this code print? int main() { auto p1 =unique_ptr<int>(new int{42}); cout << *p1; auto p2 = p1.release(); // Resets to NULL Pointer cout << *p2; (*p2)++; cout << p1.get() << endl; // Returns 0 } 424343 42430 Does not compile (illegal) Undefined behavior 42420

42420

[1928] What does this code print? int main() { auto p1 = make_shared<int>(42); auto p2 = p1; cout << *p1 << endl; cout << *p2 << endl; (*p2)++; cout << *p1 << endl; } 424343 Does not compile (illegal) 424242 Undefined behavior 424243

424243

[1931] What does this code print? int main() { auto p1 =unique_ptr<int>(new int{42}); cout << *p1; auto p2 = p1.release(); cout << *p2; (*p2)++; cout << *p2; } Undefined behavior 424343 424243 424242 Does not compile (illegal)

424243

What prints here? int i = 5; while (--i) cout << i; cout << endl;

4321

What prints here? int i = 5; while (i) cout << --i; cout << endl;

43210

What prints here? int i = 5; while (i--) cout << i; cout << endl;

43210

Assume c is a char variable. Which line produces undefined behavior? string s{"guten tag"}; // 1 auto len = s.size(); // 2 auto a = s.front(); // 3 s.at(len) = a; // 4 s[len] = c; // 5

What does this code segment print? int n = 4; int& r1 = n; auto& r2 = r1; r1 = 3; r2 = 5; cout << n << endl;

Which line advances the loop? 1. string s("Hello CS 150"); 2. while (s.size()) 3. { 4. if (s.at(0) == 'C') break; 5. s = s.substr(1); 6. } 7. cout << s << endl;

Which line will not compile? int main() { vector<int> v{1, 2, 3}; auto size = v.size(); cout << v.back() << endl; // 1. cout << v.front() << endl; // 2. cout << v.at(0) << endl; // 3. cout << v.at(size) << endl; // 4. cout << v.pop_back() << endl; // 5. }

[1505] Below is a cumulative algorithm using an array and an iterator-based loop. What is printed? (Assume all includes have been added, etc.) double average(const int **beg, const int **end) { double sum = 0; size_t count = end - beg; while (beg != end) sum += *beg++; return sum / count; } int main() { int a[] = {2, 4, 6, 8}; cout << average(begin(a), end(a)) << endl; } 4 5 Does not compile 6 Endless loop when run; likely crashes.

[1512] Below is a cumulative algorithm using an array and an iterator-based loop. What is printed? (Assume all includes have been added, etc.) double average(const int *beg, const int *end) { double sum = 0; size_t count = end - beg; while (beg != end) sum += *beg++; return sum / count; } int main() { int a[] = {2, 4, 6, 8}; cout << average(a + 1, a + 3) << endl; } 5 2 Does not compile 4 3

[1525] What is printed? int mystery(const int a[], size_t n) { int x = a[n - 1]; while (n > 0) { n--; if (a[n] > a[x]) x = a[n]; } return x; } int main() { int a[] = {1, 3, 5, 3, 5, 4}; cout << mystery(a, 6) << endl; }

[1531] What is printed? const int* mystery(const int* p, size_t n) { const int *x = p, *y = p + n; while (++p != y) { if (*p > *x) x = p; } return x; } int main() { int a[] = {1, 2, 3, 4, 5, 1}; cout << *(mystery(a, 6)) << endl; } 0 5 2 None of these 4

[1532] What is printed? const int* mystery(const int* p, size_t n) { const int *x = p, *y = p + n; while (++p != y) { if (*p > *x) x = p; } return x; } int main() { int a[] = {1, 2, 3, 4, 5, 1}; cout << *(mystery(a, 6)) << endl; } 4 5 2 None of these 0

[1815] What is the value of a[0][2] after this runs? int cnt = 0, a[2][3]; for (int i = 0; i < 3; i++) for (int j = 0; j < 2; j++) a[j][i] = ++cnt; 6 4 2 5 3

[2313] What is the value of r(74757677)? int r(int n) { if (n) return (n % 10 == 7) + r(n / 10); return 0; } 3 5 Does not compile 8 Stack overflow

What prints here? int i = 5; while (i) cout << i--; cout << endl;

54321

The file temp.txt contains "If I saw an Aardvark, I would scream!". What prints? ifstream in("temp.txt"); char c; int i = 0; while (in.get(c)) { if (tolower(c) == 'a') i++; } cout << i << endl;

[1344] Examine the following code. What is stored in b after it runs. int f(int * p, int x) { **p = x ** 2; return x / 2; } . . . int a = 3, b, c; c = f(&b, a);

[1507] Below is a cumulative algorithm using an array and an iterator-based loop. What is printed? (Assume all includes have been added, etc.) double average(const int *beg, const int *end) { double sum = 0; size_t count = end - beg; while (beg != end) sum += *beg++; return sum / count; } int main() { int a[] = {2, 4, 6, 8}; cout << average(begin(a) + 1, end(a)) << endl; } 6 4 5 Does not compile Endless loop when run; likely crashes.

[1807] What prints? int a[4][2] = {1, 2, 3, 4, 5, 6, 7}; cout << a[2][1] << endl; Undefined (out of bounds) 6 Illegal declaration. Does not compile. 5 4 // 0 1 // 0 { 1, 2 // 1 3, 4 // 2 5, 6 // 3 7, 0 }

[1814] What is the value of a[1][2] after this runs? int cnt = 0, a[2][3]; for (int i = 0; i < 3; i++) for (int j = 0; j < 2; j++) a[j][i] = ++cnt; 4 6 2 5 3

[1825] How many (int) elements are in this array? int a[2][3]; 3 2 5 4 6

[1837] What prints? int x = 0; int a[2][3] = {{1, 2, 3}, {4, 5, 6}}; for (const auto& r : a) for (const auto& c : r) x++; cout << x << endl; 3 2 Undefined (out of bounds) 6 Illegal; will not compile

[1839] What prints? int x = 0; int a[2][3] = {{1, 2, 3}, {4, 5, 6}}; for (const auto& r : a) for (const auto& c : r) x = c; cout << x << endl; 21 Undefined (out of bounds) 6 15 Illegal; will not compile

[2301] Given the function below, what does cout << mystery(3) print? int mystery(int n) { if (n < 2) return 1; return n * mystery(n - 1); } 6 120 2 24

[2317] What is the value of r(88788)? int r(int n) { if (!n) return 0; return (n % 10 == 8) + (n % 100 == 88) + r(n / 10); } 4 1 5 6 Stack overflow

[2336] What is the value of r(3)? int r(int n) { if (n < 2) { return 1; } return n * r(n - 1); } 24 2 120 6

Which of these lines are illegal? [1] int n1 = 4; [2] double n2 = 3.145; [3] unsigned char n3 = 158; [4] int n4 = n2; [5] int& r1 = n1; [6] int& r2 = n2; [7] double& r3 = n1; [8] const int& r4 = n2;

6 7

What prints? int main() { cout << 2000 / 3.0 << endl; }

6.66667e-02

What prints? int main() { cout << setprecision(2) << 2000 / 3.0 << endl; }

6.67e02

What is the output of the following? int i = 0, j = 0; while (i < 125) { i = i + 2; j++; } cout << j << endl;

What prints? int main() { cout << fixed << 2000 / 3.0 << endl; }

666.666667

What prints? int main() { cout << fixed << setprecision(2) << 2000 / 3.0 << endl; }

666.67

Which lines compile and return string objects? [1] string s{"shiver me timbers"}; [2] auto len = s.size(); [3] s.front() = 'S'; [4] s.back() = "S"; [5] s[len] = 'X'; [6] s.substr(0, 1) = "W"; [7] auto a = s.substr(0, 100); [8] auto b = s.substr(4, 3); [9] auto c = s.substr(len);

7 8 9

[1718] What is the result of running this line of code? char s[] = "hi\0hey"; 3 chars 'h', 'i', '\0' stored in s. strlen(s) is 2. 6 chars, 'h','i','\0','h','e','y' stored in s. strlen(s) is 2. 7 chars, 'h','i','\0','h','e','y','\0' stored in s. strlen(s) is 2. 7 chars, 'h','i','\0','h','e','y','\0' stored in s. strlen(s) is 6. This is a syntax error.

7 chars, 'h','i','\0','h','e','y','\0' stored in s. strlen(s) is 2.

[1803] What prints? Assume 4 bytes per int. int a[][2] = {0}; cout << sizeof(a) << endl; 16 12 4 8 Illegal declaration. Does not compile.

How many lines of output are printed? int i = 0; while (i != 9) { cout << "Loop Execution" << endl; i++; }

How many times is this loop entered? (That is, how many times is i printed?) for (int i = 1; i < 10; i++) cout << i; cout << endl;

[1812] What prints when this runs? int a[2][3] = {1, 2, 3, 4, 5, 6}; cout << a[0][2] + a[1][2] << endl; 5 10 7 8 9 // 0, 1, 2 // 0 { 1, 2, 3 // 1 4, 5, 6 }

[1819] What prints? int cnt = 0, a[4][5]; for (int i = 0; i < 5; i++) for (int j = 0; j < 4; j++) a[j][i] = cnt++; cout << a[1][2] << endl; 11 9 19 8 14

[2302] If you write mystery(10), how many times is the function called? int mystery(int n) { if (n <= 2) return 1; return n * mystery(n - 1); } 120 10 6 9

[2311] What is the value of r(126)? int r(int n) { if (n >= 10) return n % 10 + r(n / 10); return n; } 3 6 13 10 9

[1520] What is printed here? (Assume all includes have been added.) int odds(int a[], size_t len) { int sum = 0; for (size_t i = 0; i < len; i++) if (a[i] % 2 == 1) sum += a[i]++; return sum; } int main() { int a[] = {1, 3, 5}; cout << odds(a, 3) << odds(a, 2) << odds(a, 1) << endl; } 999 900 300 941 Does not compile

900

Which operator is the insertion operator?

What header file do you include to call the isupper() function?

What header is needed to use the sqrt() function?

<cmath>

[1706] To process array-style (C) strings in C++, use the header: <string> <cstring> <c-string> "cstring.h"

What header is needed for output formatting?

What header is needed to use cin and cout?

[1925] To use any of C++ smart pointer types, include the header: <memory> <ptr> <new> <smart_ptr> <alloc>

What header file to you need to include to use the standard C++ error-handling classes?

The C++ string class is defined in the header:

What header is needed to use the string type?

Which operator is the extraction operator?

End a block of source code Meaning of value returned from a function Required to document functions, global variables and constants Begin a block of source code Your name Information about the library When was it created? Name and meaning for a parameter

@endcode @return @file @code @author @version @date @param

Which of these documentation tags are used in a function comment?

@return @param @endcode @code

Which of these documentation tags are used in a file comment?

@version @author @date @file

What prints? void fn(int, double, double&) { cout << "A" << endl; } void fn(int, int, double&) { cout << "B" << endl; } void fn(int, int, double) { cout << "C" << endl; } void fn(int, int, int) { cout << "D" << endl; } int main() { auto n = 3.5; fn(1, 2.5, n); }

What prints here? auto a = 'A'; switch (a) { case 64: cout << "?"; case 65: cout << "A"; case 66: cout << "B"; } cout << endl;

A But should be AB

[2438] Manager is derived from Employee. Which of the following statements are true? Every Manager constructor will implicitly call the default Employee constructor An Employee constructor will implicitly call the default Manager constructor A Manager constructor can pass data to an Employee constructor All of the above statements are true

A Manager constructor can pass data to an Employee constructor

body

A block containing statements that implement the function's actions.

[2423] Which one of the following is an example of the "substitution principle"? A base-class object must be used in place of a derived class object A base-class object can be used in place of a derived class object A derived class object must be used in place of a base-class object A derived class object can be used in place of a base-class object

A derived class object can be used in place of a base-class object.

[1537] What is the name for this algorithm? template <typename T> ostream& mystery(ostream& out, const T* p, size_t n) { out << '['; if (n) { out << p[0]; for (size_t i = 1; i < n; i++) out << ", " << p[i]; } out << "]"; return out; } A cumulative algorithm An extreme values algorithm An iterator algorithm None of these A fencepost algorithm

A fencepost algorithm

fruitful function

A function that calculates and returns a value

procedure

A function that carries out an action instead of calculating a value.

function

A named block of code that carries out an action or calculates a value.

On line 2, b is: int main() { a = 3; // 1 const int b = 7; // 2 a = b; // 3 }

A non-modifiable lvalue

[2333] Which of the following is true about using recursion? Recursion always helps you create a more efficient solution than other techniques. A recursion eventually exhausts all available memory, causing the program to terminate A recursive computation solves a problem by calling itself with simpler input. None of the listed options.

A recursive computation solves a problem by calling itself with simpler input.

[2330] Which of the following statements is correct about a recursive function? A recursive function must never call another function. A recursive function calls itself. A recursive function must be simple. A recursive function must call another function.

A recursive function calls itself.

What kind of error is this? error: expected ';' after expression

A syntax error

Assume vector<double> speed(5); Which line throws a run-time error?

ANSWER --> None of these cout << speed[speed.size()]; speed[0] = speed.back() speed.front() = 12; speed.erase(speed.begin());

Which line fails to work correctly? template <typename T> void print(const T& item) { cout << item << endl; }

ANSWER --> None of these print(2 + 2); print(string("goodbye")); print(3 + 2.2); print("hello");

Assume s1 and s2 are C++ string objects. Which of these calls is illegal? template <typename T> void addem(T a, U b) { cout << a << " + " << b << "->" << (a + b) << endl; }

ANSWER --> None of these addem(1.5, 2); addem(s1, s2); addem(3, 4) addem(4.5, 5.5);

[2008] What is true about user-defined types implemented using structures with public data members? you cannot enforce the invariant properties of your types modifications to the character of the data members requires clients to rewrite code they may be more error-prone than types developed using classes clients can directly modify the data members of a variable

ANSWER → All of these

Which statement is false? The elements in a vector:

ANSWER → None of these Are accessed by using an index or subscript Each use the same amount of memory Are are all of the same type Are homogeneous

v.push_back(3);

Adds a new element to the end of v

In Computer Science, a collection of variables that have distinct names and types is called a structure. User-defined types that combine multiple values into a single type are called scalar types It is legal to include the same struct definition multiple times, as long as the definitions are exactly the same. In C++, objects have reference semantics; object variables refer to, but do not contain the data members. A structure definition creates a new variable. In C++, a collection of variables that have distinct names and types is called a record. In C++, a collection of variables that have distinct names and types is called a structure. User-defined types that contain a single value are called structured types. This is the correct syntax for a C++ scoped enumeration. enum WEEKEND {SATURDAY, SUNDAY}; Structure variables should be passed to functions by value. User-defined scalar types are created with the struct or class keywords in C++. Structures are homogenous data types. User-defined types that combine multiple values into a single type are called scalar types. Structures data members must all be of the same type. When passing a structure variable to a function, use non-const reference if the function should not modify the actual argument. The built-in primitive data types such as int, char and double are structured data types. When passing a structure variable to a function, use const reference if the intent is to modify the actual argument. The standard library types such as string and vector are scalar data types. The following code is illegal. struct {int hours, seconds; } MIDNIGHT{0, 0};

All are False

This is the correct syntax for a C++ scoped enumeration. enum class WEEKEND {SUNDAY, SATURDAY=6}; Structures are heterogeneous data types. The built-in primitive data types such as int, char and double are scalar data types. User-defined scalar types are created with the enum class keywords in C++. User-defined types that contain a single value are called scalar types. The standard library types such as string and vector are structured data types. You may create a structure variable as part of a structure definition. The following is an anonymous structure. struct {int hours, seconds; } MIDNIGHT{0, 0}; Structure variables should be passed to functions by reference. When passing a structure variable to a function, use non-const reference if the intent is to modify the actual argument. The following code is legal. struct {int hours, seconds; } MIDNIGHT{0, 0}; User-defined types that combine multiple values into a single type are called structured types. A structure member may be a variable of a different structure type. In C++, objects have value semantics; object variables contain the data members. Structures data members may each have a different type. C++ has two ways to represent records, the class and the struct. This is the correct syntax for a C++ scoped enumeration. enum class WEEKEND {SATURDAY, SUNDAY}; It is illegal to include the same struct definition multiple times, even if the definitions are exactly the same. When passing a structure variable to a function, use const reference if the function should not modify the actual argument. In Computer Science, a collection of variables that have distinct names and types is called a record. This is the correct syntax for a C++ plain enumeration. enum WEEKEND {SATURDAY, SUNDAY};

All are True

[1314] These pointer should point to "nothing". Which is not correctly initialized? Star *ps = NULL; vector<int> *vp(0); int *pi = nullptr; double *pd{}; All are correctly initialized to point to nothing

All are correctly initialized to point to nothing

[2022] Which of these are part of the implementation? class Time { Time(); long get() const; void set(long); private: long seconds; }; The accessor and the mutator All of these are part of the implementation None of these are part of the implementation The data member seconds The constructor

All of these are part of the implementation

[1828] What is true about the command line in C++? I. The first argument is the name of the program II. Command line arguments are passed in an array III. Use main(int argc, char* argv[]) I and III All of these are true I only II and III II only

All of these are true

[2203] The BigNum class allows you to create arbitrarily large numbers, without loss of precision. Which of the following operators (which are all valid) cannot be used, assuming that the BigNum constructor is non-explicit? BigNum a{9.2573e27}; auto c = a / 100.0; ≔ const BigNum BigNum::operator/(const BigNum& rhs)const; const BigNum operator/(const BigNum& lhs, const BigNum& rhs); const BigNum operator/(const BigNum& lhs, double rhs); All of these can be used ≕

All of these can be used

[2511] Below is a class hierarchy. Which assignment will fail to compile? class Pet { . . . }; class Puppy : public Pet { . . . }; class Kitty : public Pet { . . . }; class Ducky : public Pet { . . . }; Pet pet; Puppy pup; Kitty kit; Duck duck; pet = kit; pet = pup; Puppy& pr = pup; Pet* p = &duck; All of these will compile

All of these will compile

[2216] The Point class represents x,y coordinates in a Cartesian plane. Which line of code appears in the blank? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: int x() const { return x_; } int y() const { return y_; } bool operator==(const Point& rhs) const { return ____________________________; } }; x_ == rhs.x_ && y_ == rhs.y_ x() == rhs.() && y() == rhs.y() this->x() == rhs.() && this->y() == rhs.y() this->x_ == rhs.x && this->y_ == rhs.y_ All of these will work

All of these will work

[2003] Which of these is a constructor? class Alligator { public: Alligator(double w); void eat(); string toString() const; private: double weight; }; weight toString() Alligator() None of these eat()

Alligator()

[1833] What prints? int a[5][3] = { { 1, 2, 3}, { 4, 5, 6}, { 7, 8, 9}, {10, 11, 12}, {13, 14, 15} }; int *p = &a[0][0]; cout << (p + 5) << endl; 4 An address Illegal; will not compile 1 Undefined (out of bounds)

An address

prototype

Another name for a function declaration

[1608] Below is a mystery() function with no types for its parameter. What does the function do? void mystery(a, b&, c, d, e) { b = 0; while (in >> n && b < c) a[b++] = n; } Inserts input into a partially-filled array Deletes elements from a partially-filled array Appends input to the end of a partially-filled array.

Appends input to the end of a partially-filled array.

Used by compiler to produce object code.

Assembler

Which of these five concepts are illustrated here? int main() { extern int a; a = 3; }

Assignment Declaration

Literals like 3 and 7 are always: On line 3, b is: int a = 3; // 1 int a = 7; // 2 a = b; // 3

B O T H : rvalue

[2527] What prints when this code is run? (Note that struct is used instead of class only to make all members public and to make the code shorter). #include <string> #include <iostream> using namespace std; struct B { 🌺string str() const { return "B"; }}; struct D1 : public B { virtual string str() const { return "D1"; }}; struct D2 : public B { string str() const { return "D2"; }}; struct D3 : public D1 { string str() const { return "D3"; }}; int main() { B *p1(new D1), *p2(new D2), *p3(new D3); cout << p1->str() << p2->str() << p3->str() << endl; } BBB BBD3 D1BD3 D1D2D3

BBB

[1829] Why is the command-line argc always at least 1? Because argv[0] is the name of the program running Because the argv[] array is a special case that starts at 1 Because argv[0] is unused Because argv[0] is a pointer named this It is not. If there are no arguments passed, then argc is 0

Because argv[0] is the name of the program running

[2104] The _____________ of an object is implemented by the object's member functions. Class Identity State Object Behavior

Behavior

[2509] Below is a class hierarchy for card games. Assuming that these are the only classes and that the concrete classes are correctly completed, which of the following definitions will not compile? class Hand { std::vector<Card> cards; public: void add(const Card&); Card get(size_t index) const; virtual int score() const; }; class PokerHand : public Hand { . . . }; class BlackjackHand : public Hand { . . . }; class GoFishHand : public Hand { . . . }; Hand* h = new Hand; BlackjackHand* h = new Hand; Hand* h = new BlackjackHand; GoFishHand gfh; Hand& h = gfh;

BlackjackHand* h = new Hand;

[2420] What does a derived class inherit from its base class? Only data Neither data nor behavior Only behavior Both data and behavior

Both data and behavior

[2427] How can a derived class override a base class function? Nothing is required in the derived class - this is automatically provided by inheritance It is impossible for the derived class to override a base class function By providing a new implementation for a function, tagged with the override reserved word By providing a new implementation for a function with the same name and parameter types

By providing a new implementation for a function with the same name and parameter types

[2348] Assuming that you need to write a recursive function calc_prod(int n) to calculate the product of the first n integers, which of the following would be a correct way to simplify the input for the recursive call? Call calc_prod(n - 1) and multiply by n. Call calc_prod(n + 1) and multiply by n. Call calc_prod(n - 2) and multiply by n. Call calc_prod(1) and multiply by n.

Call calc_prod(n - 1) and multiply by n.

[2349] Suppose you need to write a recursive function power(double x, int n) that calculates x to the power of n. Which of the following would be a correct way to implement the function power? Call power(x, n) and multiply by (n - 1). Call power(x, n - 1) and multiply by n. Call power(x - 1, n) and multiply by x. Call power(x, n - 1) and multiply by x.

Call power(x, n - 1) and multiply by x.

Which of these program organization schemes does not work?

Call your functions and define them afterwards.

In C++, characters of the type char:

Can be preceded by signed or unsigned for use as small integers Generally use 8 bits of storage. Use the ASCII character set Are defined for the first 127 characters

In C++, characters of type char:

Can be preceded by signed or unsigned for use as small integers Generally use 8 bits of storage. Use the ASCII character set Are defined for the first 127 characters

[2517] Below is a class hierarchy. Which assignments are illegal? class Widget { . . . }; class Label: public Widget { . . . }; class Button: public Widget { . . . }; class Text: public Widget { . . . }; class TextArea: public Text { . . . }; class TextLine: public Text { . . . }; class Container: public Widget { . . . }; class Canvas: public Container { . . . }; class Window: public Container { . . . }; Text* p = new TextArea; Widget* p = new Window; Canvas* p = new Container; None of these are illegal Widget* p = new Widget;

Canvas* p = new Container;

[2436] Which one of the following Car member functions is called by this statement? AeroCar acar1(2000.0, 200.0); class Car { public: Car(); Car(double); void setSpeed(double); double getSpeed() const; }; class AeroCar : public Car { public: AeroCar(); AeroCar(double); AeroCar(double, double); void setHeight(double); double getHeight() const; }; AeroCar::AeroCar(double h, double s) : Car(s), height(h) { } int main() { AeroCar acar(2000.0, 200.0); } double getSpeed() const Car(double) void setSpeed(double) Car()

Car(double)

[2441] The AeroCar class is derived from Car and it overrides the setSpeed(double) member function. In the AeroCar setSpeed function, how can the Car setSpeed function be called? The Car setSpeed function cannot be called from the AeroCar::setSpeed function ::setSpeed(newSpeed) Car::setSpeed(newSpeed) Car::setSpeed() super::setSpeed(newSpeed)

Car::setSpeed(newSpeed)

[2430] The Pet base class defines void setName(const string&). Cat is derived from Pet, but does not define setName(). What is true? Cat class inherits the setName function setName() cannot be called on Cat objects Cat overrides the setName function The Cat class will not compile because it does not define setName

Cat class inherits the setName function

[2522] What prints when this code is run? #include <string> #include <iostream> using namespace std; class Shape { public: 🌺 virtual string toString() const { return "Shape"; } }; class Circle : public Shape { public: string toString() const { return "Circle"; } }; class Triangle : public Shape { public: string toString() const { return "Triangle"; } }; int main() { Shape* s1 = new Circle; Shape* s2 = new Triangle; cout << s1->toString() << s2->toString() << endl; } ShapeShape CircleTriangle ShapeTriangle Compiles but prints something else

CircleTriangle

[2103] A(n) ___________ is a template or blueprint specifying the data attributes and behaviors for a group of similar objects. Behavior State Class Object Identity

Class

[2613] Examine the class hierarchy below. Assume that both derived classes are concrete and completely defined. What happens when a PokerHand object is passed to the non-member draw() function, assuming that the function makes use of the virtual functions overridden in PokerHand? class Hand { std::vector<Card> cards; public: Hand() = default; virtual ~Hand() = default; void add(const Card&); virtual int score() const = 0; virtual void sort(); bool operator<(const Card& rhs) const; }; class PokerHand : public Hand { . . . } class BlackjackHand : public Hand { . . . } void draw(const Hand h) { . . . } The code compiles but fails to link The hand is drawn appropriately The code does not compile because the argument is of the wrong type Code compiles, but the parameter is treated as a Hand object, not a PokerHand, so it is not drawn correctly

Code compiles, but the parameter is treated as a Hand object, not a PokerHand, so it is not drawn correctly

[1817] What prints? int a[3][2] = {{3,2,3}}; // too many initializers for 'int [2]' cout << a[0][0] << a[1][0] << endl; 00 30 Code does not compile 33 31

Code does not compile

[1707] What happens here? char * s = "CS150"; strcpy(s, "CS50"); cout << s << endl; The code will not compile Code will compile (with warnings), but crash when run "CS50" "CS500" "CS150CS50"

Code will compile (with warnings), but crash when run.

Which of these are true? int main() { vector<int> v{1, 2, 3}; for (const auto& e : v) e = 0; cout << v.at(0) << endl; }

Code will not compile

Converts processed source code to object code.

Compiler

What kind of error is this? ex1.cpp:6:5: error: use of undeclared identifier 'a' a = 4; ^

Compiler error (something is missing when compiling)

[2115] The following code: #include <string> class Xynoid { double a{3.14}; int b = 42; std::string c; }; int main() { Xynoid x; } Compiles and links. All members uninitialized Does not compile. Compiles and links. Two members uninitialized Compiles and links. All members initialized Compiles but does not link.

Compiles and links. All members initialized

[2114] The following code: #include <string> class Xynoid { double a; int b; std::string c; }; int main() { Xynoid x; } Does not compile. Compiles and links. Two members uninitialized Compiles and links. All members initialized. Compiles but does not link. Compiles and links. All members uninitialized

Compiles and links. Two members uninitialized

[1502] Below is a cumulative algorithm using an array and a range-based loop. What is printed? (Assume this is inside main() with all includes, etc.) int a[] = {2, 4, 6, 8}; int sum; for (auto e : a) sum += e; cout << "sum->" << sum << endl; Compiles and runs, but results are undefined. sum->20 sum->8 Does not compile. Cannot use range-loop on arrays. Compiles but crashes with an endless loop.

Compiles and runs, but results are undefined.

[2117] The following code: #include <string> class Xynoid { double a{3.14}; int b = 42; std::string c; public: Xynoid() = default; Xynoid(double x, int y, std::string z); }; int main() { Xynoid x; Xynoid z(1, 2, "fred"); } Does not compile. Compiles and links. All members uninitialized Compiles but does not link. Compiles and links. All members initialized Compiles and links. Two members uninitialized

Compiles but does not link

[2119] What happens here? #include <iostream> using namespace std; class Dog { int age_= 7; public: Dog(int a); int get() const; }; Dog::Dog(int a): age_(a) { } int Dog::get() const { return age_; } int main() { Dog a(5); Dog b(a); Dog c = 10; cout << a.get() << b.get() << c.get() << endl; } Line Dog b(a); does not compile. No suitable constructor. Segmentation fault when line Dog c = 7 run. Compiles, links: prints 5510 Compiles, links: prints 5710 Line Dog c = 10; do

Compiles, links: prints 5510

The makefile for h04 is missing int main() { }

Compiles, runs and returns 0 to the O/S

[2303] What does this function do? int mystery(int n) { if (n == 1) return 1; return n * mystery(n-1); } Computes the reverse of the input n Computes the Gauss series (sum) of 1..n Computes the Factorial number n Computes the Fibonacci number n Produces a stack overflow

Computes the Factorial number n

[2304] What does this function do? int mystery(int n) { if (n < 2) return 1; return mystery(n-1) + mystery(n-2); } Computes the Gauss series (sum) of 1..n Computes the Factorial number n Computes the Fibonacci number n Computes the reverse of the input n Produces a stack overflow

Computes the Fibonacci number n

[2306] What does this function do? int mystery(int n) { if (n == 1) return 1; return n + mystery(n-1); } Computes the Factorial number n Computes the reverse of the input n Computes the Fibonacci number n Produces a stack overflow Computes the Gauss series (sum) of 1..n

Computes the Gauss series (sum) of 1..n

[2307] What does this function do? int mystery(int n, int m) { if (n == 0) return m; return m * 10 + mystery(n / 10) + n % 10; } Produces a stack overflow Computes the reverse of the input n Computes the Factorial number n Computes the Gauss series (sum) of 1..n Computes the Fibonacci number n

Computes the reverse of the input n

[2445] What is printed? class Counter { public: Counter(int c) : counter(c) {} virtual void add(int n) { counter += n; } void display() { cout << "Count->" << counter; } private: int counter; }; class DoubleCounter : public Counter { public: DoubleCounter(int c) : Counter(c * 2) {} void add(int n) { Counter::add(n * 2); } }; int main() { DoubleCounter counter(10); counter.add(5); counter.display(); } Counter->25 Counter->15 Counter->20 Counter->30

Counter->30

What does this code do? ifstream in("temp.txt"); char x; int i{0}; while (in.get(x)) i++; cout << i << endl;

Counts the number of characters in the file

What does this code do? ifstream in("temp.txt"); string x; int i{0}; while (getline(in, x)) i++; cout << i << endl;

Counts the number of lines in the file

What does this code do? ifstream in("temp.txt"); string x; int i{0}; while (in >> x) i++; cout << i << endl;

Counts the number of words in the file

What prints? string str = "Hello"; for (size_t i = str.size() - 1; i >= 0; i--) cout << str.at(i);

Crashes when run

Which of these are true? int main() { vector<int> v{1, 2, 3}; for (auto i = v.size() - 1; i >= 0; i--) // out of range for >= cout << v.at(i) << " "; cout << endl; }

Crashes when run Prints 3 2 1 Issues a compiler warning, but no error

Assume that the file scores.txt does not exist. What happens? ofstream out("scores.txt"); out << "Peter" << " " << 20 << endl; out << "John" << " " << 50 << endl;

Creates a new file, scores.txt and writes two lines of text.

vector<int> v;

Creates the empty vector []

vector<int> v(1);

Creates the vector [0]

vector<int>v[2, 3];

Creates the vector [2, 3]

vector<int>v(2,3);

Creates the vector [3,3]

[2610] Which member function is called? class Performer { public: virtual void sing() const; }; class Crooner : public Performer { public: void sing() const; }; int main() { Performer* p = new Crooner; p->sing(); } Crooner::sing() Performer::sing() Neither of these Illegal (does not compile)

Crooner::sing()

[2526] What prints when this code is run? (Note that struct is used instead of class only to make all members public and to make the code shorter). #include <string> #include <iostream> using namespace std; struct B { virtual string str() const { return "B"; }}; struct D1 : public B { string str() const { return "D1"; }}; struct D2 : public B { string str() const { return "D2"; }}; struct D3 : public D1 { string str() const { return "D3"; }}; int main() { B *p1(new D1), *p2(new D2), *p3(new D3); cout << p1->str() << p2->str() << p3->str() << endl; } BBB BBD3 D1D2D3 Compiles but prints something else

D1D2D3

[2210] The Date class represents a day on a calendar. Examine the code shown. Which operator is called? Date d{2018, 7, 4}; auto e = ++d; const Date Date::operator++(int); Date& Date::operator++(int); None of these const Date Date::operator++(); Date& Date::operator++();

Date& Date::operator++();

[2211] The Date class represents a day on a calendar. Examine the code shown. Which operator is called? Date d{2018, 7, 4}; auto e = ++d; ≔ const Date operator++(Date&); Date& operator++(Date&, int); Date& operator++(Date&); const Date operator++(Date&, int); None of these ≕

Date& operator++(Date&);

Allows you to run your program in a controlled environment.

Debugger

Which of these five concepts are illustrated here? int main() { extern int a; }

Declaration Definition

Which of these five concepts are illustrated here? int main() { int a; }

Declaration Definition

[1609] Below is a mystery() function with no types for its parameter. What does the function do? void mystery(a, b&, c, d, e) { for (i = d; i < b; i++) a[i] = a[i + 1]; b--; } Inserts input into a partially-filled array Deletes elements from a partially-filled array Appends input to the end of a partially-filled array.

Deletes elements from a partially-filled array

[1323] What is true about an uninitialized pointer?

Dereferencing it is undefined behavior

Assume the user types "brown cow" when this code runs. What prints? char c; cout << cin.get(c) << endl;

Does not compile

Assume the user types "brown cow" when this code runs. What prints? char c; cout.put(cin.get(c));

Does not compile

What prints here? auto a = 1; switch (a) { case 1: cout << "1"; case 2: cout << "2"; case 3: } cout << endl;

Does not compile

What prints here? auto a = 3, b = 3; cout << a == b ? "panda" : "tiger" << endl;

Does not compile

What prints? string str = "Hello"; for (auto i = 0, len = str.size(); i < len; i++) cout << str.at(i);

Does not compile

[1712] What happens here? char *s1 = "CS150"; char s2[] = s1; // C++ forbids converting a string constant to 'char*' s2[0] = 'X'; cout << s1 << endl; "XS150" "CS150" Crashes when run Does not compile Undefined behavior

Does not compile

[2534] What prints when this code is run? #include <string> #include <iostream> #include <vector> using namespace std; class Shape { public: virtual void iam() const; }; class Square : public Shape { public: void iam() const; }; class Oval: public Shape { public: void iam() const; }; void Shape::iam() const { cout << "Shape"; } void Square::iam() const { cout << "Square"; } void Oval::iam() const { cout << "Oval"; } void iam(const Shape& s) { s.iam(); } int main() { vector<Shape&🌺> v = {Shape(), Square(), Oval()}; for (auto& e : v) iam(e); cout << endl; } ShapeShapeOval ShapeSquareOval ShapeShapeShape ShapeSquareShape Does not compile

Does not compile

[1932] What does this code print? int main() { auto p1 =unique_ptr<int>(new int{42}); cout << *p1; auto p2 = p1; cout << *p2; (*p2)++; cout << *p2; } Does not compile (illegal) 424242 424243 Undefined behavior 424343

Does not compile (illegal)

[2217] The Point class represents x,y coordinates in a Cartesian plane. Which line of code appears completes this operator which transforms a Point by dx and dy? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } Point operator+(int dx, int dy) const { return _________________________; } }; Point(x() + dx, y() + dy); Point(x_ + y_, dx + dy); Does not compile, changes arity of operator. Does not compile; must be a non-member function. Does not compile; must have one user-defined type as argument.

Does not compile, changes arity of operator.

[2116] The following code: #include <string> class Xynoid { double a{3.14}; int b = 42; std::string c; public: Xynoid(double x, int y, std::string z); }; int main() { Xynoid x; } Compiles and links. Two members uninitialized Compiles but does not link. Compiles and links. All members uninitialized Compiles and links. All members uninitialized Does not compile.

Does not compile.

[2027] What prints here? class Car { double speed; public: Car(); Car(double s); double get() const; }; Car::Car() { speed = 10; } Car::Car(double s) { speed = s; } double Car::get() const { return speed; } int main() { Car c1(), c2(5); cout << c1.get() << c2.get() << endl; } Undefined; c1 not initialized 05 15 105 Does not compile; c1 is not an object

Does not compile; c1 is not an object

[2220] The Point class represents x,y coordinates in a Cartesian plane. Which line of code appears completes this operator? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } }; const Point operator++(Point& p, int n) { Point temp(p); . . . return _________________________; } *this Does not compile; cannot change data members of object; no mutators. temp Does not compile; must be a member function. Does not compile; changes arity of operator; should be unary, not binary.

Does not compile; cannot change data members of object; no mutators.

[2223] The Point class represents x,y coordinates in a Cartesian plane. Which line of code appears completes this operator? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } }; Point& operator++(Point& p) { . . . return _________________________; } Does not compile; cannot change data members of object; no mutators. Does not compile; changes arity of operator; should be unary, not empty. p Does not compile; must be a non-member function. *this

Does not compile; cannot change data members of object; no mutators.

[1503] Below is a cumulative algorithm using an array and a range-based loop. What is printed? (Assume this is inside main() with all includes, etc.) int a[] = {2, 4, 6, 8}; int sum = 0; for (auto e : a) sum += e; cout << "sum->" << e << endl; Does not compile; e is undefined. Does not compile. Cannot use range-loop on arrays. Compiles and runs, but results are undefined. sum->20 sum->8

Does not compile; e is undefined.

[2224] The Point class represents x,y coordinates in a Cartesian plane. Which line of code appears completes this operator? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } }; Point& operator+=(Point& rhs) { x_ += rhs.x(); y_ += rhs.y(); return _________________________; } Does not compile; missing const at the end of the operator header. *this Does not compile; changes arity of operator; should be unary, not binary. Does not compile; must be a member operator. rhs

Does not compile; must be a member operator.

[2218] The Point class represents x,y coordinates in a Cartesian plane. Which line of code appears completes this operator which transforms a Point by dx and dy? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } }; Point operator+(int dx, int dy) { return _________________________; } ≔ Does not compile; must have one user-defined type as argument. Does not compile, changes arity of operator Does not compile; must be a member function Point(x_ + y_, dx + dy) Point(x() + dx, y() + dy) ≕

Does not compile; must have one user-defined type as argument.

[2225] The Point class represents x,y coordinates in a Cartesian plane. Which line of code appears completes this operator? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } }; Point& operator+=(Point& lhs, const Point& rhs) { __________________________________________ return lhs; } ≔ lhs.x_ += rhs.x(); lhs.y_ += rhs.y(); lhs.x() += rhs.x(); lhs.y() += rhs.y(); Does not compile; rhs must not be const Does not compile; no access to private members of lhs Does not compile; changes arity of operator; should be unary, not binary ≕

Does not compile; no access to private members of lhs.

[2219] The Point class represents x,y coordinates in a Cartesian plane. Which line of code appears completes this operator which returns the address of the Point object in memory? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } }; Point operator@(const Point& p) { return __________________; } Does not compile; uses a non-operator symbol. Does not compile; changes arity of operator. Does not compile; must be a member function. *&p &p

Does not compile; uses a non-operator symbol.

[2602] What does this code mean? class X : Y { . . . }; Each X object is-implemented in terms of Y Each X object uses- a Y object Every X object is-a Y object Every X object has-a Y object Every Y object is-a X object

Each X object is-implemented in terms of Y

[2604] What does this code mean? class X { double x = Y().balance(); . . . }; Every X object has-a Y object Every Y object is-a X object Every X object is-a Y object Each X object uses- a Y object Each X object is-implemented in terms of Y

Each X object uses- a Y object

The following code is logically correct. What is the semantically correct prototype for mystery()? vector<double> v{1, 2, 3}; mystery(v);

Either mystery(const vector<int>&); or mystery(vector<int>&); could be correct.

[2435] The Manager class is derived from the Employee class. Manager defines a constructor, but does not explicitly call an Employee constructor. Which constructor is called by the Manager constructor? class Employee { public: Employee(); Employee(const string&); Employee(double); Employee(const string&, double); }; Employee(const string&, double); Employee(); Employee(const string&); Employee(double);

Employee();

[2106] _________________ is the Object-Oriented design principle and technique that enforces data hiding. Abstraction Inheritance Dynamic Binding Polymorphism Encapsulation

Encapsulation

Which of these are true? int main() { vector<int> v{1, 2, 3}; for (auto i = v.size() - 1; i >= 0; i--) cout << v[i] << " "; cout << endl; }

Endless loop (will likely crash, but not necessarily) Issues a compiler warning, but no error Prints 3 2 1

[1508] Below is a cumulative algorithm using an array and an iterator-based loop. What is printed? (Assume all includes have been added, etc.) double average(const int *beg, const int *end) { double sum = 0; size_t count = end - beg; while (beg != end) sum += *beg++; return sum / count; } int main() { int a[] = {2, 4, 6, 8}; cout << average(end(a), begin(a)) << endl; } Does not compile Endless loop when run; likely crashes. 5 6 4

Endless loop when run; likely crashes.

[2603] What does this code mean? class X { Y y; . . . }; Every X object is-a Y object Every Y object is-a X object Every X object has-a Y object Each X object is-implemented in terms of Y Each X object uses- a Y object

Every X object has-a Y object

[2601] What does this code mean? class X : public Y { . . . }; Each X object uses- a Y object Every Y object is-a X object Each X object is-implemented in terms of Y Every X object is-a Y object Every X object has-a Y object

Every X object is-a Y object

[2335] Which of the following is a key requirement to ensure that recursion is successful? Every recursive call must simplify the computation in some way A recursive solution should not be implemented to a problem that can be solved iteratively There should be special cases to handle the most complex computations directly A recursive function should not call itself except for the simplest inputs

Every recursive call must simplify the computation in some way.

[1617] Below is insert(), a template function that works with a partially-filled array. The function inserts the argument e into the array, in sorted order. The function returns true if it succeeds, false otherwise. The function contains an error; what is the error? template <typename T> bool insert(T* a, size_t& size, size_t MAX, T e) { if (size >= MAX) return false; size_t i = 0; while (i < size) { if (a[i] > e) break; i++; } for (j = size; j > i; j--) a[j] = a[j - 1]; a[i] = e; return true; } The value is inserted into the wrong position The second loop should start at i and go up to size Every time the function is called, an array element is "lost" The function writes over memory outside the array when it should not

Every time the function is called, an array element is "lost"

The code shown here: auto n = 3; if (n = 0) cout << "n is 0" << endl; else cout << "n is " << n << endl;

Executes the false branch Displays "n is 0" Contains an embedded assignment

calling

Executing, running or invoking the function

>> cout << cin \n endl

Extraction or input operator Analogous to Java's System.out Insertion or output operator Similar to Java's Scanner objects Escape character Stream manipulator

What is the output? auto x = 40; if (x <= 40) cout << "F"; if (x <= 75) cout << "C"; if (x <= 90) cout << "B"; cout << endl;

FCB

A 2D array address expression is the equivalent of: *(address + (row * height + col))

False

A class specifies the attributes of the objects it creates through the definition of embedded functions, called member functions.

False

A constructor that takes no arguments is called the working constructor.

False

A function that is marked with the keyword inline should be placed in the implementation .cpp file.

False

A pointer that goes out of scope before deleting the memory it points to is called a dangling pointer.

False

A pointer that goes out of scope before deleting the memory it points to is called a double delete.

False

A pointer-like object that can be used to automatically manage memory allocated on the heap is called a raw pointer.

False

A reference variable has a different identity than the variable it refers to.

False

A structure is an interface paired with an implementation.

False

A template function may be declared in a header file but must be defined in an implementation file.

False

A unique_ptr uses a reference count to manage how many pointers point to an object.

False

Assume the vector v contains [1, 2, 3]. v.erase(0); changes v to [2, 3]. Vector subscripts begin at 1 and go up to the vector size. The statement v.insert(v.end(), 3) is undefined because end() points past the last element in the vector. Assume that v contains [1, 2, 3]. The result of writing cout << v.at(4); is undefined. The C++ term for classes like vector are generic classes. The statement v.insert(v.begin(), 3) inserts the element 3 into the vector v, overwriting the exiting element at index 0. The push_back member function adds elements to the end of a vector as long as there is room for the elements. The declaration: vector<int> v(10); creates a vector object containing uninitialized elements. The declaration: vector<int> v(10, 5); creates a vector object containing five integers. The declaration: vector<string> v(5); creates a vector containing five null pointers. In the declaration: vector<int> v; the word vector represents the object's base type. The declaration: vector<int> v; creates a vector variable but no vector object. Assume that v contains [1, 2, 3]. The result of writing cout << v.at(4); is a compiler error. Vector subscripts begin at 1 and go up to the vector size. A vector consists of named members. The declaration: vector<int> v(10, 5); is illegal. Assume vector<double> v; Writing cout << v.back(); throws a runtime exception. Assume that v contains [1, 2, 3]. The result of writing cout << v[4]; is a compiler error. The declaration: vector<int> v = new vector<>(); creates a vector object with no elements. The pop_back member function adds elements to the end of a vector.

False

Assuming p is a pointer to a single variable allocated on the heap, the statement delete p; sets the pointer to nullptr so that the memory can be reused for another allocation.

False

Assuming p is a pointer to a single variable allocated on the heap, the statement delete[] p; returns the allocated memory back to the operating system for reuse.

False

Assuming p is a pointer to a single variable allocated on the stack, the statement delete p; returns the allocated memory back to the operating system for reuse.

False

Assuming p is a pointer to the first variable in an array allocated on the heap, the statement delete p; returns the allocated memory back to the operating system for reuse.

False

Assuming str is a string object, this syntax is legal in both Java and C++. Does this code work correctly in both languages? if (str == "quit") . . .

False

C-strings use the strcpy() function for concatenation. The characters for the C-string char * s1 = "hello"; are stored in user memory and may be modified. strcmp(s1, s2) returns true if s1 and s2 contain the same characters. The strlen() function returns the allocated size of a C-string allocated as an array. The C-string type is part of the standard library, not built into the C++ language. C-string assignment uses the = operator. The length of a C-string is stored explicitly in its length data member The allocated size for the C-string char s1[1024] = "hello"; is 6 characters, while the effective size is 5 characters. C-string assignment uses the strcat() function. The strcat() function cannot overflow the storage allocated for the destination buffer. The strncpy() function always appends a trailing NUL when the copy is finished. strcmp(s1, s2) returns a negative number if s1 is lexicographically "greater than" s2. The sizeof operator returns the effective size of a C-string allocated as an array. The strncpy() function is straightforward and easy to use. strcmp(s1, s2) returns a positive number if s1 is lexicographically "less than" s2. You can compare two C-strings, s1 and s2, by using the == operator. C-strings use the + operator for concatenation. C-strings are char pointers to the first character in a sequence of characters, terminated with a '0' character. When writing programs that interact with your operating system, either Windows, Mac OSX or Linux, you will normally use the C++ library string type, rather than the older C-string type. The C-string literal "cat" contains 3 characters. The strcpy() function expands the destination string to make sure it is large enough to hold the source string.

False

Calling a function like to_string<int>(3.5) is known as implicit instantiation.

False

Calling break() terminates a program immediately and passes an error code back to the operating system.

False

Classes whose objects need to be sorted should overload <.

False

Constructors always have the same name as the class and a return type of void.

False

Constructors always have the same name as the class, except that the constructor name is capitalized.

False

Constructors always have the same name as the class, preceded by the tilde character (~).

False

Constructors must be explicitly called after an object is created.

False

Data member is the term used in C++ for what is called a method in Java

False

Explicitly initializing an array like this: int a[3] = {1, 2, 3}; requires the size and the number of elements supplied to be the same. You may use any kind of integral variable to specify the size of a built-in C++ array. The elements of a C++ string array with no explicit initialization, created in a function will be set to null. Explicitly initializing an array like this: int a[3] = {1, 2, 3}; requires the size to be the same or smaller than the number of elements supplied. In C++ using == to compare one array to another is illegal. The allocated size of a built-in C++ array may be changed during runtime If img is a pointer to the first byte in an image loaded into memory, Pixel is a structure as defined in your textbook, you can create a Pixel pointer pointing to the image by writing: Pixel *p = static_cast<Pixel *>(img); The reinterpret_cast instruction produces a temporary value by converting its argument. In C++ initializing an array with the contents of another is permitted. C++ arrays use bound-checking when you access their elements with the at() member function. The elements of a C++ array created in a function are allocated on the heap. In C++ assigning one array to another is permitted. C++ arrays throw an out_of_bounds exception if you access an element outside the array. In C++ an array variable and the array elements are separate. The array variable contains the address of the first element in the array. In C++ printing an array name prints the value of the first element in the array. The elements of a C++ int array with no explicit initialization, created in a function will be set to zero. C++ arrays can be allocated with a size of 0. The static_cast instruction changes way that a pointer's indirect value is interpreted. The size of the array is stored along with its elements. The allocated size of a built-in C++ array may be changed during runtime A forward reference can be used when you want to use a structure as a data member without first defining the entire structure. The elements of a C++ array created outside of a function are allocated on the stack. If p is a pointer to a structure, and the structure contains a data member x, you can access the data member by using the notation: *p->x C++ arrays offer built-in member functions for inserting and deleting. Explicitly initializing an array like this: int a[] = {1, 2, 3}; only works in C++ 11.

False

Freeing unused memory that was allocated elsewhere in your program is done in C++ using a garbage collector.

False

If a member function is in the private section of a class, it cannot be called from other member functions of the class.

False

If str = "hello", then str.size() > -1.

False

If the new operator cannot allocate memory, C++ returns nullptr.

False

If you do not create a constructor for your class, C++ will synthesize a working constructor for you.

False

If your class does not have a constructor, the compiler will synthesize a working constructor for you.

False

In C++ a char may be one, two or three bytes, when using UTF-8.

False

In C++ the only difference between structures and classes is that member functions are private by default in structures.

False

In C++ the only difference between structures and classes is that member functions are public by default in classes A class definition normally appears in a .cpp file The member function int& hours(); provides read-only access to the hours property (however it is stored) You may add = default; to the prototype of any constructor to allow the compiler to synthesize one for you The semicolon following a class definition is optional Member functions that initialize the data members of a new object are called accessors Using classes for user-defined types means that you cannot change the data representation without affecting the users of your class

False

In C++ there is actually no difference between structures and classes

False

In C++ there is actually no difference between structures and classes.

False

In C++ you use the keyword public or private before each data member or member function to indicate its access privileges.

False

In C++, as in Java pure virtual member functions may not have an implementation The C++ facility that allows a derived class to have multiple base classes is known as interface inheritance In C++, an Abstract Base Class is any class that has one or more virtual member functions The istream class in the C++ standard library uses multiple inheritance Since an abstract class cannot be instantiated, it is illegal to have references of abstract types Using public inheritance to derive Stack from vector is a good design because vector provides all of the capabilities that a Stack requires An abstract class is a class that contains no data members Constructing an instance of an abstract class is legal, provided you do not initialize it Consider the Shape class hierarchy, along with Circle, Square and Star from your text. The Shape class is a concrete class What Java calls a static method is called a pure virtual member function in C++ If a class is abstract, you may create instances, but not pointers of that class An abstract class may, but is not required to, override its pure virtual (abstract) member functions Composition models an IS-A relationship between classes Composition can be used to create adapter classes that change the implementation of one class to meet the needs of another Private inheritance models an IS-A relationship between classes In C++, public inheritance can be used to create adapter classes An abstract class is a class that contains only virtual member functions Using the keyword abstract to the heading of a virtual member function converts it to a pure virtual member function Abstract classes provide a set of capabilities that derived classes my inherit In adapter classes, the member functions override superclass member functions to provide new behavior Consider the Shape class hierarchy, along with Circle, Square and Star from your text. The Circle class is an abstract class

False

In C++11 you can initialize members in the initializer list using braces, parentheses or the assignment operator syntax.

False

In a 2D array the first subscript represents the columns and the second the rows.

False

In a constructor, objects can be initialized immediately after the opening brace of the constructor, before any other code has been run.

False

In a partially-filled array, the capacity may be less than the array's size. When inserting a value into a partially-filled array, in ascending order, the insertion position may be the same as capacity. When inserting elements into a partially-filled array, the array should be declared const. When comparing two partially-filled arrays for equality, both arrays should not be declared const. When deleting an element from a partially-filled array, it is an error if the index of the element to be removed is < size. When inserting a value into a partially-filled array, elements following the insertion position are shifted to the left. In a partially-filled array, the size represents the allocated size of the array. In a partially-filled array, the capacity represents the effective size of the array. In a partially-filled array, all of the elements are not required to contain meaningful values When inserting an element into a partially-filled array, it is an error if size < capacity. In a partially-filled array, all of the elements contain meaningful values When deleting elements from a partially-filled array, the array should be declared const. In a partially-filled array capacity represents the number of elements that are in use. When searching for the index of a particular value in a partially-filled array, the array should not be declared const. When inserting a value into a partially-filled array, in ascending order, the insertion position is the index of the first value smaller than the value.

False

Inheritance enforces the principle of data hiding.

False

Initialization of data members occurs according to the order they are listed in the initializer list.

False

Member functions that change the state of an object are called accessors.

False

Member functions that change the state of an object are called constructors.

False

Member functions that initialize the data members of a new object are called mutators.

False

Memory for global variables is allocated when the program is loaded from disk. This is known as automatic allocation.

False

Memory for global variables is allocated when the program is loaded from disk. This is known as dynamic allocation.

False

Memory for local variables is allocated on the stack when their definitions are encountered during runtime. This is known as dynamic allocation.

False

Memory for local variables is allocated on the stack when their definitions are encountered during runtime. This is known as static allocation.

False

Mutator member functions are allowed to read data members, but not change them

False

Mutator member functions are allowed to read data members, but not change them.

False

Mutator member functions should always end in the keyword const

False

Object behavior is implemented by data member.

False

Overloaded operators are functions that use special names that begin with the keyword overloaded.

False

Physically, a 2D array is stored as a rectangular grid of columns and rows.

False

Physically, a 2D array is stored as a single linear, contiguous array with the elements for each column following the elements for the previous column in memory.

False

Polymorphism enforces the principle of data hiding.

False

Programmers using class-derived objects, directly manipulate the data members of those objects.

False

Requesting a block of memory from the operating system as the program runs is known as automatic allocation.

False

Requesting a block of memory from the operating system as the program runs is known as static allocation.

False

Side-effect operators, such as increment or short-hand assignment, should be written as non-member operators.

False

Smart pointers may point to objects allocated on the stack.

False

Suppose you have two classes related by inheritance: Dog and Poodle. According to the principle of substitutability, a function void walk(Dog& d) will accept a Poodle as an argument.

False

Suppose you have two classes related by inheritance: Dog and Poodle. According to the principle of substitutability, a function void walk(Poodle& p) will accept a Dog as an argument.

False

Suppose you have two classes related by inheritance: Dog and Poodle. According to the rules of inheritance, Dog is a specialization of Poodle.

False

Symetric operators, where the user-defined type may appear on the left or the right, should be written as member operators.

False

Tell the compiler that you intend to override a base class function by adding the keyword override as an annotation before the function header Putting the keyword final at the end of a non-virtual member function heading prohibits derived classes from overriding that function Virtual functions invoked through an object use late binding to decide which function to call The composition relationship is informally known as is-a Virtual member functions are implemented by adding a new pointer, called a vtable, to every object that contains at least one virtual function If you make a class final then you must make all of its member functions final as well In private inheritance derived classes inherit the interface of the base class, but not its implementation The public inheritance relationship is informally known as implemented-with If a derived class redefine a non-virtual base-class function it causes a syntax error The public inheritance relationship is informally known as has-a Non-virtual functions always use late binding to decide which function to call Waiting until runtime to determine which function to call is known as early binding

False

The I/O operators should always be written as member operators.

False

The arithmetic operators, such as addition, subtraction and multiplication for type T should return a T&.

False

The arithmetic operators, such as addition, subtraction and multiplication for type T should return a T.

False

The attributes of an object refers to the combination of values stored in its data members.

False

The compiler determines which overloaded function to call by looking at the type of value the function returns.

False

The constructor initializer list is preceded by a colon and followed by a semicolon.

False

The constructor that is used to initialize all of an object's fields is called the default constructor.

False

The constructor that takes no arguments is called the working constructor.

False

The expression *this can be returned from non-member operators.

False

The getline() function is part of the string class.

False

The heading of a try block can contain ellipses in place of a parameter

False

The implementation of a class normally appears entirely inside the class .cpp file.

False

The implementation of a member function from the Time class would look something like this: int Time.hours() const {...}.

False

The implementation of a member function from the Time class would look something like this: int hours() const {...}.

False

The interface of a class includes all items in the header file.

False

The line: cin >> n; throws a runtime exception if n is an int and it tries to read the input "one".

False

The line: ifstream in("x"); throws a runtime exception if a file x cannot be found

False

The member function int hours() const; provides read-write access to the hours property (however it is stored).

False

The order of the catch blocks does not affect the program.

False

The parameter declarations int p* and int[] p mean the same thing. After passing an array to a function, sizeof(a)/sizeof(a[0]) will tell the number of elements in the array. If p points to the first element in [1, 3, 5] then cout << *++p prints 1. If p points to the first element in [1, 3, 5] then cout << ++*p prints 1. The library function begin(a) returns a pointer to the element right before the first in the array a. For embedded systems, vector is preferred over arrays. For systems programming (such as operating systems), vectors are used more often than arrays. For an equivalent number of elements, a vector will use less memory than an array. The expression *p++ means the same as (*p)++. An array passed to a function f(const int *a, ...) may have its elements changed. The elements of a vector may be allocated on the stack. For an equivalent number of elements, a vector will use more memory than an array. The algorithm that prints elements separated by commas is called a cumulative algorithm. The algorithm that finds the position of the largest element in an array is called a cumulative algorithm. The algorithm that finds the position of the largest element in an array is called a cumulative algorithm. After passing an array to a function, sizeof(a) will tell you the array's allocated size, but not the number of elements. If p points to the first element in [1, 3, 5] then cout << *p++ prints 3. The library function end(a) returns a pointer to the last element in the array a. A vector generally has higher performance than an array. If size_t len = 0; then len - 1 is the smallest possible unsigned number. The expression begin(a) + 1 returns a pointer to the first element in the array a. The function mystery(const int*, const int*) likely employs a counter-controlled loop. An array passed to a function is passed by reference.

False

The parameter names left and right are commonly used with overloaded operators.

False

The preprocessor operates on code after it has been compiled.

False

The preprocessor operates on code before it has been compiled.

False

The prototype for a member subtraction operator for the type T is: const T operator-(const T& lhs, const T& rhs);

False

The prototype for a non-member addition operator for the type T is: const T operator+(const T& rhs) const;

False

The release() function deletes the raw pointer that a unique_ptr contains, and then sets that pointer to a new value.

False

The reset() function returns the raw pointer that a unique_ptr contains, before setting that pointer to nullptr.

False

The short-hand assignment operators for type T should return a const T.

False

The signature for the postfix decrement operator (of type T) is: T& operator--();

False

The signature for the prefix increment operator (of type T) is: const T operator++(int);

False

The state of an object refers to the names and types of its data members.

False

The statement #if abs(-3) > 2 is legal.

False

The statement new int; allocates a default-initialized integer on the heap.

False

The statement new int; allocates an uninitialized integer on the stack.

False

The statement new int[3] = {1, 2, 3}; allocates an array of three initialized integers on the heap.

False

The statement new int[3](); is a syntax error.

False

The statement new int[3]; allocates a single initialized integer on the heap.

False

The statement new int{3}; allocates an array of three integers on the heap

False

The statement new int{3}; allocates an array of three integers on the heap.

False

The statement new int{}; is a syntax error.

False

The subscript operators may be written as a member operator or as a non-member operator.

False

The toupper() member function ignores case when it searches.

False

The two parts of a class are a private interface and a public implementation.

False

To allocate memory on the stack, C++ uses the new operator.

False

Using a pointer to access the memory it points to after the pointer has been deleted is called a double delete.

False

Using a pointer to access the memory it points to after the pointer has been deleted is called a memory leak.

False

Using classes for user-defined types means that you cannot enforce restrictions on data member access.

False

Using encapsulation such as that used with structures, risks accidental data corruption.

False

Using structures for user-defined types means that you can change the data representation without affecting the users of your data type.

False

Using structures for user-defined types means that you can enforce restrictions on data member access.

False

When initializing a 2D, each column must have its own set of braces.

False

When initializing a 2D, each row must have its own set of braces.

False

When passing a 2D array to a function, the array parameter must explicitly list the size for all dimensions except for the last, like: void f(int a[3][], size_t n);

False

When you throw an exception, control immediately returns from the current function

False

With classes, the public interface includes the member functions that allow clients to access object data in a safe way as well as the data members themselves.

False

With inheritance, the class you build upon is called a derived class in C++.

False

With inheritance, the class you build upon is called a subclass in C++.

False

With inheritance, the class you build upon is called a superclass in C++.

False

With inheritance, the new class you create is called a base class in C++.

False

With inheritance, the new class you create is called a subclass in C++.

False

With inheritance, the new class you create is called a superclass in C++.

False

With operator overloading, you may use any symbol to define a new operator.

False

You can pass the 2D array int a[3][3] to the function f(int *a, size_t r, size_t c) by calling f(a, 3, 3).

False

You can pass the 2D array int a[3][3] to the function f(int a[3][], size_t n) by calling f(a, 3).

False

You can pass the 2D array int a[3][3] to the function f(int a[][], size_t r, size_t c) by calling f(a, 3, 3).

False

You can pass the first column of the 2D array int a[3][3] to the function f(int *a, size_t n) by calling f(a[0], 3).

False

You cannot use a range-based loop on a 2D array.

False

You may not overload the indirection operator, the unary *.

False

You may not overload the subscript ([]) operator.

False

You may overload operators for the built-in types.

False

You may overload the conditional operator ?:.

False

You must use the ordinary meaning of an operator when you overload it. It would be impossible to redefine subtraction to mean addition, for instance.

False

In a while loop, (condition) is followed by a semicolon. A while loop is a hasty or unguarded loop.

False False

An undeclared error message is a run-time error An undeclared error message is a linker error

False⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ False

Explain this output. Why is nothing printed? #include <iostream> using namespace std; int main() { cout << "Hello, World"; } make example ./example

File not saved

What does this code do? int x = 0; vector<int> v{1, 3, 2}; for (auto e : v) x = e; cout << x << endl;

Finds the last element in v Prints 2

[2612] Examine the class hierarchy below. Assume that both derived classes are concrete and completely defined. Which line of code is illegal: class Hand { std::vector<Card> cards; public: Hand() = default; virtual ~Hand() = default; void add(const Card&); virtual int score() const = 0; virtual void sort(); bool operator<(const Card& rhs) const; }; class PokerHand : public Hand { . . . } class BlackjackHand : public Hand { . . . } Hand h PokerHand ph; Hand* hp = new PokerHand; PokerHand ph; Hand& hr = ph; BlackjackHand* bjp = new BlackjackHand;

Hand h

[2407] A(n) ____________ relationship exists between two classes when one class contains data members that are instances of the other class Is-A Implemented-As Has-A Uses-A

Has-A

Assume the user enters Inigo Montoya when prompted. What prints? cout << "What's your name: "; string name; cin >> name; cout <<"Howdy " + name + "!";

Howdy Inigo!

[2444] What is printed? class Pet { public: Pet(const string& n) : name(n) {} virtual void info() { cout << "My name is " << name << "."; } private: string name; }; class Cat : public Pet { public: Cat(const string& n) : Pet(n) {} void info() { cout << "I am a cat. "; Pet::info(); } }; int main() { Cat cat = Cat("Felix"); cat.info(); } I am a cat. My name is Felix. My name is Felix. I am a cat. I am a cat. My name is Felix.

I am a cat. My name is Felix.

[2415] Assume you have a Student object named bill. Which of these statements would be legal? bill.name = "Bill Gates"; // I bill.setName("Bill Gates"); // II cout << bill.getName(); // III bill.studentID = 123L; // IV cout << bill.getID(); // V II, III, IV, V IV and V II, III, V All of them None of them

II, III, V

[2416] Assume that the following code appears inside a member function or constructor of the Student class. Which of these statements would be legal?? name = "Bill Gates"; // I setName("Bill Gates"); // II name = name.substr(1); // III studentID = 123L; // IV studentID = getID() * 2; // V II, IV and V II, III, V II, III, IV, V All of them None of them

II, IV and V

[1616] Below is insert(), a template function that works with a partially-filled array. The function inserts the argument e into the array, in sorted order. The function returns true if it succeeds, false otherwise. The function contains an error; what is the error? template <typename T> bool insert(T* a, size_t& size, size_t MAX, T e) { if (size < MAX) return false; size_t i = 0; while (i < size) { if (a[i] > e) break; i++; } for (j = size; j > i; j--) a[j] = a[j - 1]; a[i] = e; size++; return true; } The value is inserted into the wrong position The second loop should start at i and go up to size When a value is inserted, it erases one of the existing values If the array is full, the function overwrites memory outside the array

If the array is full, the function overwrites memory outside the array.

[1615] Below is insert(), a template function that works with a partially-filled array. The function inserts the argument e into the array, in sorted order. The function returns true if it succeeds, false otherwise. The function contains an error; what is the error? template <typename T> bool insert(T* a, size_t& size, size_t MAX, T e) { if (size < MAX) return false; size_t i = 0; while (i < size) { if (a[i] > e) break; i++; } for (j = size; j > i; j--) a[j] = a[j - 1]; a[i] = e; size++; return true; } The value is inserted into the wrong position The second loop should start at i and go up to size When a value is inserted, it erases one of the existing values If there is room to insert, the function returns false instead of true

If there is room to insert, the function returns false instead of true

[1806] What prints? Assume 4 bytes per int. int a[][] = {{1, 2}, {3, 4}}; cout << sizeof(a) << endl; 4 12 16 8 Illegal declaration. Does not compile.

Illegal declaration. Does not compile.

[1831] What prints? int a[5][3] = { { 1, 2, 3}, { 4, 5, 6}, { 7, 8, 9}, {10, 11, 12}, {13, 14, 15} }; int *p = &a[0][0]; cout << p[1][2] << endl; // invalid types 'int[int]' for array subscript Undefined (out of bounds) 6 2 Illegal; will not compile An address

Illegal; will not compile

[1836] What prints? int x = 0; int a[2][3] = {{1, 2, 3}, {4, 5, 6}}; for (auto r : a) for (auto c : r) x++; // 'r' was not declared in this scope cout << x << endl; Undefined (out of bounds) 6 Illegal; will not compile 2 3

Illegal; will not compile

This code illustrates the ______ idiom. auto n = 3; if (n % 2 == 1) n = -n; if (n < 0) n++; if (n % 2 = 0) n--;

Independent if statements

How many lines of output are printed? int count = 0; while (count != 9) { cout << "Monster Mash" << endl; if ((count % 2) == 0) { count++; } else { count--; } }

Infinite

What prints here? int i = 5; while (i); cout << i--; cout << endl;

Infinite loop

[2107] _________________ is the Object-Oriented design feature that allows you to create a new class by using an existing class as a starting point, extending it to add new attributes and behaviors. Abstraction Inheritance Dynamic Binding Polymorphism Encapsulation

Inheritance

[2118] The constructor implemented below has an error. What is it? #include <string> class Xynoid { double a{3.14}; int b = 42; std::string c; public: Xynoid() = default; Xynoid(double x, int y, std::string z); }; Xynoid::Xynoid(double x, int y, std::string z) : c(z), b(y), a(x) { } Constructor parameters are in the wrong order Initializers use the wrong parameter values There is no error. It is fine. Initializers are in the wrong order. There is no code in the body of the constructor

Initializers are in the wrong order.

What is wrong with this IPO code fragment? cout << "Name: "; string name; cout << "Hello, " << name << endl; cin >> name;

Input occurs after output

[1610] Below is a mystery() function with no types for its parameter. What does the function do? void mystery(a, b&, c, d, e) { for (i = b; i > d; i--) a[i] = a[i - 1]; a[d] = e; b++; } Inserts input into a partially-filled array Deletes elements from a partially-filled array Appends input to the end of a partially-filled array.

Inserts input into a partially-filled array

[2105] Objects are _________________ of a particular class. Instances Abstractions Identifiers Interfaces Encapsulations

Instances

[2506] Below is a class hierarchy for card games. What happens when showScore() is called? class Hand { std::vector<Card> cards; public: void add(const Card&); Card get(size_t index) const; int score() const; }; class PokerHand : public Hand { . . . }; class BlackjackHand : public Hand { . . . }; class GoFishHand : public Hand { . . . }; void showScore(const Hand& h 🌺) { cout << h.score() << endl; } . . . PokerHand ph; . . . showScore(ph 🌺); // what happens here? It does not compile because you should pass ph instead of &ph It calls the Hand::score() function because score() is not virtual It calls the PokerHand::score() function if one has been defined It does not compile because ph is not a Hand object so a pointer mismatch error The PokerHand portion of ph is sliced off and it becomes a Hand object

It calls the Hand::score() function because score() is not virtual

[2504] Below is a class hierarchy for card games. What happens when showScore() is called? class Hand { std::vector<Card> cards; public: void add(const Card&); Card get(size_t index) const; virtual int score() const; }; class PokerHand : public Hand { . . . }; class BlackjackHand : public Hand { . . . }; class GoFishHand : public Hand { . . . }; void showScore(const Hand* h 🌺) { cout << h.score() << endl; } . . . PokerHand ph; . . . showScore(&ph 🌺); // what happens here? It calls the PokerHand::score() function if one has been defined It does not compile because ph is not a Hand object so a pointer mismatch error The PokerHand portion of ph is sliced off and it becomes a Hand object It does not compile because you should pass ph instead of &ph It calls the Hand::score() function because score() is virtual

It calls the PokerHand::score() function if one has been defined

[2505] Below is a class hierarchy for card games. What happens when showScore() is called? class Hand { std::vector<Card> cards; public: void add(const Card&); Card get(size_t index) const; virtual int score() const; }; class PokerHand : public Hand { . . . }; class BlackjackHand : public Hand { . . . }; class GoFishHand : public Hand { . . . }; void showScore(const Hand& h 🌺) { cout << h.score() << endl; } . . . PokerHand ph; . . . showScore(ph 🌺); // what happens here? The PokerHand portion of ph is sliced off and it becomes a Hand object It calls the Hand::score() function because score() is virtual It calls the PokerHand::score() function if one has been defined It does not compile because ph is not a Hand object so a pointer mismatch error It does not compile because you should pass ph instead of &ph.

It calls the PokerHand::score() function if one has been defined

[2019] What is true about a mutator member function? None of these It changes one or more data members It return information about an object's internal state Its prototype ends with const Its presence means that a class is immutable

It changes one or more data members

[1715] What is true about a? char a[] = "Sup?"; It is an array with sizeof 4 It is an array with sizeof 5 It is a C-string with strlen 5 It is a pointer to an array of 4 characters

It is an array with sizeof 5

To allow f() to change the argument passed here, the parameter str should be declared as: void f( . . . str); int main() { f("hello"); }

It is not possible for f() to change the argument passed here.

What is true about string::size_type?

It is the same as size_t It is returned from the string size() member function It is returned from the string length() member function It is an unsigned integer type of some size You may create variables of that type

What is the purpose of the throw statement?

It is used to pass control to an error handler when an error situation is detected.

[1623] Below is removeDupes(), a template function leaves only unique values in a partially-filled array. The function returns the number of elements removed. The function contains an error; what is the error? template <typename T> int removeDupes(T* a, size_t& size) { int count = 0; for (size_t i = 0; i < size; i++) { for (size_t j = i + 1; j < size; j++) { if (a[i] == a[j]) { // duplicate size--; count++; for (size_t k = j; k < size; k++) a[k] = a[k + 1]; } } } return count; } The array parameter should be const T It removes some duplicates, but not all of them It returns a different number than the actual elements removed It produces undefined behavior by exceeding the bounds of the array

It removes some duplicates, but not all of them

[2020] What is true about an accessor member function? It is never used when a class is immutable It returns information about an object's state It changes one or more data members Its prototype may not include the keyword const None of these

It returns information about an object's state

What happens when this code fragment runs in C++ 11? istringstream in("one"); int n; in >> n;

It sets an error state in in.

What happens when this code fragment runs? istringstream in(".5"); int n; in >> n;

It sets an error state in in.

What happens when this code fragment runs in C++ 11? cout << stoi("one") << endl;

It throws a runtime exception

[1908] The variable *p: void f( ) { int *p = new int = {42}; } ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Stores the value 42 in all versions of C++ It's undefined → Code does not compile. It's uninitialized Stores a memory address Stores the value 42 in C++11 only ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

It's undefined → Code does not compile.

[1903] The variable *p: void f( ) { int *p = new int; } Stores a memory address Stores the value 0 It's uninitialized

It's uninitialized

Unix and C Fortran Simula Berkeley Systems Distribution Unix C++ GNU, GCC and Free Software

Ken Thomson and Dennis Ritchie John Backus O. Dahl & K. Nygaard Bill Joy Bjarne Stroustrop Richard Stallman

Below is the main function from the f2c program in Chapter 1. Which line(s) contain a output statement? int main() { 15 cout << "Enter a temperature in fahrenheit: "; 16 double fahr; 17 cin >> fahr; 18 double celsius = convert(fahr); 19 cout << "Converted: " << fahr << "F -> " << celsius << "C" << endl; return 0; }

Line 15 Line 19

Below is the main function from the f2c program in Chapter 1. Which line(s) contain a variable defintion? int main() { 15 cout << "Enter a temperature in fahrenheit: "; 16 double fahr; 17 cin >> fahr; 18 double celsius = convert(fahr); 19 cout << "Converted: " << fahr << "F -> " << celsius << "C" << endl; return 0; }

Line 16 line 18

Below is the main function from the f2c program in Chapter 1. Which line(s) uses the character input stream? int main() { 15 cout << "Enter a temperature in fahrenheit: "; 16 double fahr; 17 cin >> fahr; 18 double celsius = convert(fahr); 19 cout << "Converted: " << fahr << "F -> " << celsius << "C" << endl; return 0; }

Line 17

Below is the main function from the f2c program in Chapter 1. Which line(s) contain a function call? int main() { 15 cout << "Enter a temperature in fahrenheit: "; 16 double fahr; 17 cin >> fahr; 18 double celsius = convert(fahr); 19 cout << "Converted: " << fahr << "F -> " << celsius << "C" << endl; return 0; }

Line 18

Below is the main function from the f2c program in Chapter 1. Which line(s) use the insertion operator? int main() { 15 cout << "Enter a temperature in fahrenheit: "; 16 double fahr; 17 cin >> fahr; 18 double celsius = convert(fahr); 19 cout << "Converted: " << fahr << "F -> " << celsius << "C" << endl; return 0; }

Line 19 Line 15

[2121] What happens with this code? #include <string> #include <iostream> using namespace std; class Cat { string name_; public: Cat(const string& n); string get() const; }; Cat::Cat(const string& n): name_(n) {} string Cat::get() const { return name_; } int main() { string s = "Bill"; Cat b; b = s; cout << b.get() << endl; } Line beginning with: string Cat::get should not have const in implementation. Line Cat b; does not compile. No suitable constructor. Line beginning with: Cat::Cat should not have empty body Line b = s; does not compile. Type mismatch The does compile; it prints "Bill".

Line Cat b; does not compile. No suitable constructor.

[2122] What happens with this code? #include <string> #include <iostream> using namespace std; class Cat { string name_; public: Cat(); Cat(const string& n); string get() const; }; Cat::Cat(const string& n): name_(n) {} string Cat::get() const { return name_; } int main() { string s = "Bill"; Cat b; b = s; cout << b.get() << endl; } The does compile; it prints "Bill". Line beginning with: Cat::Cat should not have empty body Line b = s; does not compile. Type mismatch Line Cat b; does not compile. No suitable constructor. Line Cat b; does not link. No suitable implementation.

Line Cat b; does not link. No suitable implementation.

[2120] What happens here? #include <iostream> using namespace std; class Dog { int age_= 7; public: explicit Dog(int a); int get() const; }; Dog::Dog(int a): age_(a) { } int Dog::get() const { return age_; } int main() { Dog a(5); Dog b(a); Dog c = 10; cout << a.get() << b.get() << c.get() << endl; } Line Dog b(a); does not compile. No suitable constructor. Segmentation fault when line Dog c = 7 run. Line Dog c = 10; does not compile. Wrong type used for initializer. Compiles, links: prints 5710 Compiles, links: prints 5510

Line Dog c = 10; does not compile. Wrong type used for initializer.

[2124] What happens with this code? #include <string> #include <iostream> using namespace std; class Cat { string name_; public: Cat() = default; explicit Cat(const string& n); string get() const; }; Cat::Cat(const string& n): name_(n) {} string Cat::get() const { return name_; } int main() { string s = "Bill"; Cat b; b = s; cout << b.get() << endl; } Line beginning with: Cat::Cat should not have empty body The does compile; it prints "Bill". Line Cat b; does not compile. No suitable constructor. Line Cat b; does not link. No suitable implementation. Line b = s; does not compile. Type mismatch

Line b = s; does not compile. Type mismatch

[2125] What happens with this code? #include <string> #include <iostream> using namespace std; class Cat { string name_; public: Cat() = default; explicit Cat(const string& n); string get() const; }; explicit Cat::Cat(const string& n): name_(n) {} string Cat::get() const { return name_; } int main() { string s = "Bill"; Cat b; b = s; cout << b.get() << endl; } Line beginning with: explicit Cat::Cat should not repeat explicit in implementation Line beginning with: string Cat::get should not repeat const in implementation Line Cat b; does not compile. No suitable constructor. Line b = s; does not compile. Type mismatch The does compile; it prints "Bill".

Line beginning with: explicit Cat::Cat should not repeat explicit in implementation

[2126] What happens with this code? #include <string> #include <iostream> using namespace std; class Cat { string name_; public: Cat() = default; explicit Cat(const string& n); string get() const; }; Cat::Cat(const string& n): name_(n) {} string Cat::get() { return name_; } int main() { string s = "Bill"; Cat b; b = s; cout << b.get() << endl; } Line beginning with: string Cat::get should repeat const in implementation Line b = s; does not compile. Type mismatch The does compile; it prints "Bill". Line Cat b; does not compile. No suitable constructor. Line beginning with: Cat::Cat should not have an empty body.

Line beginning with: string Cat::get should repeat const in implementation

Combines object modules to produce an executable.

Linker

What kind of error is this? ex1.cpp:7: undefined reference to `f()'

Linker error (something is missing when linking)

Reads an executable image on disk and starts it running.

Loader

Provides instructions for building your program.

Make

[2439] Which among the following is the legal way of implementing the constructor of the Manager class that passes parameters to a base-class constructor? class Employee { public: Employee(); Employee(const string&); Employee(double); Employee(const string&, double); private: string name; double salary; }; class Manager : public Employee { public: Manager(); Manager(const string& d, const string& n, double s); private: string department; }; Manager::Manager(const string& d, const string& n, double s) : Employee(s, n) { department = d; } Manager::Manager(const string& d, const string& n, double s) : Employee() { department = d; } Manager::Manager(const string& d, const string& n, double s) : Employee(n, d) { department = d; } Manager::Manager(const string& d, const string& n, double s) : Employee(n, s) { department = d; }

Manager::Manager(const string& d, const string& n, double s) : Employee(n, s) { department = d; }

[2421] What is the primary purpose of inheritance? Model one-to-many relationships between different types of objects Model different objects which share similar performance goals Model similar objects with different data values Model similar objects with different behavior

Model similar objects with different behavior

Which of these statements apply to C++?

More efficient than Java or Python Produces native code that runs on the CPU Compiles to native code

[1705] What happens here void f() { char * s = "CS 150"; s[0] = 'X'; cout << s << endl; } Prints "XS 150" Most likely crashes when run Code compiles without warnings Code fails to compile because "CS 150" is const

Most likely crashes when run

[2426] Consider the following classes. The Vehicle class is a base class. The Car, Truck, and Motorcycle class inherit from the Vehicle class. The Sedan and SUV classes inherit from the Car class. Which of the following lists all the types of objects that cannot be passed into the function calculate_registration_fee(Car& car)? Motorcycle, Truck, and Vehicle objects Motorcycle, and Truck objects Sedan and SUV objects Sedan, SUV, and Car objects

Motorcycle, Truck, and Vehicle objects

[1333] What is printed when you run this code? int *n{nullptr}; cout << *n << endl;

No compilation errors, but undefined behavior

[1337] What is printed when you run this code? int n{}; int *p; *p = n; cout << *p << endl;

No compilation errors, but undefined behavior when run

What is the output of the following? bool token = false; while (token) { cout << "Hello World!" << endl; }

No output

[1335] What is printed when you run this code? int *p = &0; cout << *p << endl;

No output; compiler error.

[2417] Which of these data members or member functions are inherited by the Person class? getName(), setName(), studentID, getID() None of them name, getName(), setName(), getID() getName(), setName(), name studentID, name, getName(), setName(), getID()

None of them

[2538] Which member function(s) must 🌺 be overridden in Hobbit? class Creature { public: Creature(const string& name); virtual string name() const final; virtual string skills() const; virtual void addSkill(const string& skill); void print() const; }; class Hobbit : public Creature { . . . }; None of them addSkill(), skills() addSkill(), skills(), print() addSkill(), skills(), name()

None of them

Given the following structure and variable definitions, which data members are uninitialized? struct Employee { long empID{0}; std::string lastName; double salary{0}; int age = 0; }; Employee bob;

None of them (compiles)

Assume c is a char variable. What type is the expression s.last()? string s{"guten tag"}; auto len = s.size(); auto a = s.front(); s.at(len) = a; s[len] = c;

None of these

Assume c is a char variable. Which line produces a syntax error? string s{"guten tag"}; // 1 auto len = s.size(); // 2 auto a = s.front(); // 3 s.at(len) = a; // 4 s[len] = c; // 5

None of these

Below is the main function from the f2c program in Chapter 1. Which line(s) contain a function declaration? int main() { 15 cout << "Enter a temperature in fahrenheit: "; 16 double fahr; 17 cin >> fahr; 18 double celsius = convert(fahr); 19 cout << "Converted: " << fahr << "F -> " << celsius << "C" << endl; return 0; }

None of these

Given the following structure and variable definitions, which data members are default initialized? struct Employee { long empID; std::string lastName; double salary; int age; }; Employee bob{777, "Zimmerman", 5000000.0, 76};

None of these

In Line 2, what is the parameter? string s{"happy"}; auto pos = s.find('y');

None of these

This code is legal, compiles and is well defined. Which line(s) contain an input statement? int a = 5; // 1 a == 5; // 2 int b = 6; // 3 a ={b}; // 4 auto c = a == b; // 5

None of these

What is stored in data after this runs? vector<int> data{1, 2, 3}; data.pop_back();

None of these

What is stored in data after this runs? vector<int> data{1, 2, 3}; data.pop_back(0);

None of these

What kind of error is this? ~/workspace/ $ ./ex1 The Patriots won the 2018 Super Bowl

None of these

Which line in the function "skeleton" below contains an error? #include "digits.h" // 1. int firstDigit(int n) // 2. { // 3. return 0; // 4. }

None of these

Which line or lines are illegal? int a; int b = 3; int main() { a = 4; cout << a << ", " << b << endl; }

None of these

Which line reads a single word from the istream named in into the string variable word? word = in.next(); in.get(word); getline(in, word); in << word; None of these

None of these

Which lines cause runtime errors (exceptions)? [1] string s{"shiver me timbers"}; [2] auto len = s.size(); [3] s.front() = 'S'; [4] s.back() = "S"; [5] s[len] = 'X'; [6] s.substr(0, 1) = "W"; [7] auto a = s.substr(0, 100); [8] auto b = s.substr(4, 3); [9] auto c = s.substr(len);

None of these

Which of the following variables have the value null? int global; int main { string localStr; double localDouble; }

None of these

Which prototypes in the following header file contain errors? #ifndef EXAMPLE_H #define EXAMPLE_H #include <string> std::string f1(int a); int f2(double); void f3(std::string& s, int n); double f4(); #endif

None of these

[1404] Which prints the number of elements in a? int a[] = {1, 2, 3}; cout << a.length << endl; cout << sizeof(a[0]) << endl; cout << a.size() << endl; cout << sizeof(a) << endl; None of these

None of these

[1406] Which line throws and out_of_range exception? double speed[5] = {. . .}; None of these cout << speed[4] << endl; cout << speed[5] << endl; cout << speed[0] << endl; cout << speed[1] << endl;

None of these

[1428] Which expression returns the number of countries? string countries[] = {"Andorra", "Albania", . . . }; len(countries) countries.length sizeof(countries) * sizeof(countries[0]) sizeof(countries) None of these

None of these

[1434] Which array definition produces {0, 1, 2}? int SIZE = 3; int a1[SIZE]; int a2[3]; int a3[3]{}; int a4[] = {1, 2, 3}; int a5[3] = {1, 2}; a5 a3 None of these a2 a1

None of these

[1526] What is printed? int mystery(const int a[], size_t n) { int x = n - 1; while (n > 0) { n--; if (a[n] < a[x]) x = n; } return x; } int main() { int a[] = {1, 2, 5, 2, 5, 4}; cout << mystery(a, 6) << endl; } 1 2 3 None of these 4

None of these

[1921] This code: void f() { int *p = new int[3]{rand(), rand(), rand()}; if (p[1] != 0 && p[2] != 0) cout << p[0] / p[1] / p[2] << endl; delete[] p; } None of these has a double delete has a syntax error has a memory leak has a dangling pointer

None of these

[1926] Which line correctly creates a smart pointer that points to the variable x? int x = 42; unique_ptr<int[]>(&x); make_shared<int>(x); unique_ptr<int>(&x); None of these shared_ptr<int>(&x);

None of these

[1927] Which line correct creates a smart pointer that points to the variable x? int x = 42; unique_ptr<int[]>(&x); None of these shared_ptr<int>(&x); unique_ptr<int>(&x); make_shared<int>(x);

None of these

[2002] Which of these is a default constructor? class Alligator { public: Alligator(double w); void eat(); string toString() const; private: double weight; }; None of these Alligator() toString() weight eat()

None of these

[2013] What is f()? class X { public: X(int); void f() const; int g() const; void h(int); }; None of these mutator destructor constructor accessor

None of these

[2018] Which element is private? struct Val { int data_; public: Val(int); int get() const; void print() const; }; void Val::get() { return data_; } Val::Val(int n) { data_ = n; } void Val::print() const { cout << data_; } Val() None of these get() print() data_

None of these

[2111] The copy constructor for this class is: class Radio { public: Radio(); explicit Radio(double); Radio(double, int); double frequency() const; double frequency(double); }; Radio(double, int) None of these Radio(double) Radio()

None of these

[2206] The BigNum class allows you to create arbitrarily large numbers, without loss of precision. Examine the code shown. Which expression invokes the operator defined here? BigNum a{"12345.795"}, b{".95873421"}; const BigNum operator-() {...} auto c = a - b; a -= b; auto c = -b; auto c = --b; None of these

None of these

Assume vector<double> speed(5); Which line throws a runtime error?

None of these speed.erase(speed.begin()); speed.front() = 12; speed[0] = speed.back() ANSWER → cout << speed.at(speed.size());

This code illustrates the ______ idiom. auto n = 3; else if (n % 2 == 1) n = -n; else if (n < 0) n++; else if (n % 2 = 0) n--; else n = 0;

None of these are correct

[2516] Below is a class hierarchy. Which assignments are illegal? class Widget { . . . }; class Label: public Widget { . . . }; class Button: public Widget { . . . }; class Text: public Widget { . . . }; class TextArea: public Text { . . . }; class TextLine: public Text { . . . }; class Container: public Widget { . . . }; class Canvas: public Container { . . . }; class Window: public Container { . . . }; Button* p = new Button; Widget* p = new Window; Widget* p = new TextLine; Container* p = new Canvas; None of these are illegal

None of these are illegal

Given the overloaded functions prototypes and the variable definition below, which of the function calls will fail to compile? int f(int&); int f(const int&); int f(int, int); int a = 7;

None of these fail to compile

[1915] Examine this code. What goes on the blank line? void f() { int *p = new int[3]{1, 2, 3}; . . . ___________________ } delete p[]; delete p; delete p[3]; None of these is correct delete[] *p;

None of these is correct

[1918] Examine this code. What goes on the blank line? void f() { int *p = new int{3}; . . . ___________________ } delete *p; delete p[]; None of these is correct delete[] p; delete p[3];

None of these is correct

[1539] What is printed? template <typename T> ostream& mystery(ostream& out, const T* p, size_t n) { out << '['; if (n) { out << p[0]; for (size_t i = 1; i < n; i++) out << ", " << p[i]; } out << "]"; return out; } int a[] = {1,2,3,4,5,1}; mystery(cout, a, sizeof(a)) << endl; [1, 2, 3, 4, 5, 1] [1, 2, 3, 4] [1, 2, 3, 4, 5] None of these or undefined output. [1, 2, 3]

None of these or undefined output.

[1509] Below is a cumulative algorithm using an array and an iterator-based loop. What is printed? (Assume all includes have been added, etc.) double average(const int *beg, const int *end) { if (end <= beg) return 0.0 / 0.0; // nan double sum = 0; size_t count = end - beg; while (beg != end) sum += *beg++; return sum / count; } int main() { int a[] = {2, 4, 6, 8}; cout << average(end(a), begin(a)) << endl; } 4 Does not compile 5 Not a number (NaN) Endless loop when run; likely crashes.

Not a number (NaN)

[1614] Below is remove(), a template function that works with a partially-filled array. The function removes all copies of the argument e, returning the number of copies removed. The function contains an error; what is the error? template <typename T> int remove(T* a, size_t& size, T e) { int removed = 0; size_t i = 0; while (i < size) { if (a[i] == e) { removed++; size--; for (size_t j = i; i < size; i++) a[i] = a[i + 1]; } i++; } return removed; } a should be a const T* size should not be passed by reference The condition should go to while (i <= size) Not all copies of e are necessarily removed

Not all copies of e are necessarily removed

What prints? vector<int> v{1, 2, 3, 4, 5}; cout << v.pop_back() << endl;

Nothing; compile-time error

What prints? void f(const vector<int>& v) { v.at(0) = 42; } int main() { vector<int> x{1, 2, 3}; f(x); cout << x.at(0) << endl; }

Nothing; compile-time error.

[2422] Suppose that we have a Question class that contains two data members - a query and answer both of which are type string. The NumericQuestion class is derived from Question. Which of the following is true? NumericQuestion contains a numerical answer but not a query NumericQuestion contains a query and a numerical answer but no answer string It is impossible to know without examining the definition of the NumericQuestion class NumericQuestions contains both a query and an answer string.

NumericQuestions contains both a query and an answer string

The file temp.txt contains "Orange Coast College". What prints? ifstream in("temp.txt"); char c; while (in.get(c)) { if (isupper(c)) cout << toupper(c); }

OCC

What kind of error is this? Segmentation fault

Operating system signal or trap

[2520] Below is a class hierarchy. Which statements may result in slicing? class Writer { . . . }; class Pen : public Writer { . . . }; class Pencil : public Writer { . . . }; class FountainPen : public Pen { . . . }; Writer p = Writer (); Pen* p = new Writer(); Pen p = FountainPen(); Writer& p = *(new Pencil);

Pen p = FountainPen();

v.begin()

Points to the first element in v

[2510] Below is a class hierarchy for card games. Assuming that these are the only classes and that the concrete classes are correctly completed, which of the following definitions will not compile? class Hand { std::vector<Card> cards; public: void add(const Card&); Card get(size_t index) const; virtual int score() const; }; class PokerHand : public Hand { . . . }; class BlackjackHand : public Hand { . . . }; class GoFishHand : public Hand { . . . }; GoFishHand gfh; Hand* h = new Hand; PokerHand* = new Hand; Hand& h = *(new PokerHand);

PokerHand* = new Hand;

[2108] _________________ is the Object-Oriented design feature that allows you to write programs in terms of an "ideal" class, but substitute or plug-in related objects that act in different ways when your program runs. Inheritance Polymorphism Dynamic Binding Abstraction Encapsulation

Polymorphism

Performs text substitution on your source code.

Preprocessor

Which of these are true? int main() { vector<int> v{1, 2, 3}; for (auto& e : v) e = 0; cout << v.at(0) << endl; }

Prints 0

Which of these are true? int main() { vector<int> v{1, 2, 3}; for (auto e : v) e = 0; cout << v.at(0) << endl; }

Prints 1 Code runs but has no effect on v

[2331] What does this function do? void myfun(string word) { if (word.length() == 0) return; myfun(word.substr(1, word.length())); cout << word[0]; } Prints the length of the string word Prints the string word both forward and reverse Prints the string word in reverse Prints the string word

Prints the string word in reverse

[2305] What does this function do? int mystery(int n) { if (n == 1) return 1; return n * mystery(n+1); } Computes the Gauss series of n Computes the Fibonacci number n Produces a stack overflow Computes the Factorial number n Computes the reverse of the input n

Produces a stack overflow

return statement

Produces a value when the function is invoked

[2334] How can you ensure that a recursive function terminates? Call the recursive function with simpler inputs. Use more than one return statement. Provide a special case for the simplest inputs. Provide a special case for the most complex inputs.

Provide a special case for the simplest inputs

[2512] Below is a class hierarchy. Which assignment will fail to compile? class Pet { . . . }; class Puppy : public Pet { . . . }; class Kitty : public Pet { . . . }; class Ducky : public Pet { . . . }; Pet pet; Puppy pup; Kitty kit; Duck duck; pet = pup; Puppy* p = &pet; Puppy& pr = pup; Pet* p = &duck;

Puppy* p = &pet;

[2442] ChoiceQuestion is derived from the Question base class . ChoiceQuestion overrides the display() function defined in the Question base class. Which of the following will call the base class display() function from the ChoiceQuestion display() function? display() ::display() Question::display() super::display() this->display()

Question::display()

[2035] The default constructor is: class Radio { public: Radio(); explicit Radio(double); Radio(double, int); double frequency() const; double frequency(double); }; None of these Radio() Radio(double, int) Radio(double)

Radio()

[2110] The conversion constructor for this class is: class Radio { public: Radio(); explicit Radio(double); Radio(double, int); double frequency() const; double frequency(double); }; None of these Radio(double) Radio(double, int) Radio()

Radio(double)

[2109] The working constructor for this class is: class Radio { public: Radio(); explicit Radio(double); Radio(double, int); double frequency() const; double frequency(double); }; Radio(double, int) Radio(double) Radio() None of these

Radio(double, int)

Examine the following code (which is legal). Which statement is correct? struct Rectangle { int length, width; };

Rectangle r;

v.erase(v.begin());

Removes the first element in v and shifts the rest to the left

v.pop_back()

Removes the last element in v

Examine the following variables and function calls Match each item with the correct statement below. int able = 3; int baker = f1(able); cout << able << baker << endl; // 64 int charlie; f2("hello", charlie); cout << charlie << endl; // Hello Carl

Returned value --> baker Output argument (parameter) --> Charlie Input argument (parameter) --> Hello Input/output argument (parameter) --> able

v[3];

Returns a reference to the fourth element in v with no range checking

v.back();

Returns a reference to the last element in v

[1521] What does this function do? int mystery(const int a[], size_t n) { int x = n - 1; while (n > 0) { n--; if (a[n] > a[x]) x = n; } return x; } Returns the largest number in the array Returns the index of the last occurrence of the largest number in the array Returns the smallest number in the array Returns the index of the first occurrence of the largest number in the array Does not compile

Returns the index of the last occurrence of the largest number in the array

[1522] What does this function do? int mystery(const int a[], size_t n) { int x = n - 1; while (n > 0) { n--; if (a[n] < a[x]) x = n; } return x; } Returns the smallest number in the array Returns the index of the last occurrence of the smallest number in the array Does not compile Returns the index of the first occurrence of the smallest number in the array Returns the largest number in the array

Returns the index of the last occurrence of the smallest number in the array

[1524] What does this function do? int mystery(const int a[], size_t n) { int x = a[n - 1]; while (n > 0) { n--; if (a[n] > a[x]) x = a[n]; } return x; } Returns the index of the last occurrence of the smallest number in the array Does not compile Returns the largest number in the array Returns the smallest number in the array Returns the index of the first occurrence of the smallest number in the array

Returns the largest number in the array

[1533] What does this function do? double mystery(const double a[], size_t len) { double x = a[0]; for (size_t i = 1; i < len; i++) if (a[i] > x) x = a[i]; return x; } Does not compile Returns the largest number in the array Returns the smallest number in the array Undefined. Depends on the input.

Returns the largest number in the array

[1523] What does this function do? int mystery(const int a[], size_t n) { int x = a[n - 1]; while (n > 0) { n--; if (a[n] < a[x]) x = a[n]; } return x; } Returns the index of the first occurrence of the smallest number in the array Returns the largest number in the array Returns the index of the last occurrence of the smallest number in the array Returns the smallest number in the array Does not compile

Returns the smallest number in the array

[1534] What does this function do? double mystery(const double a[], size_t len) { double x = a[0]; for (size_t i = 1; i < len; i++) if (a[i] < x) x = a[i]; return x; } Returns the largest number in the array Does not compile Returns the smallest number in the array Undefined. Depends on the input.

Returns the smallest number in the array

1 cout << 10 + 1 << endl; 2 cout << (10 + 1) << endl; 3 (cout << 11) << endl;

Rule 1 precedence Rule 2 associativity Rule 3 side effect

Assume a is 14 and b is 10; what prints? string s{"feed the fish"}; cout << s.substr(a, b) << endl;

Runtime error

What kind of error is this? terminate called after throwing an instance of 'std::out_of_range'

Runtime error (throws exception when running)

What value is stored in a after this runs? string s{"ABC"}; auto a = s.substr(4, 5);

Runtime error because start (4) must bet 0..3

v.at(3);

Safely returns a reference to the fourth element in v

[2521] What prints when this code is run? #include <string> #include <iostream> using namespace std; class Shape { public: 🌺virtual string toString() const { return "Shape"; } }; class Circle : public Shape { public: string toString() const { return "Circle"; } }; class Triangle : public Shape { public: string toString() const { return "Triangle"; } }; int main() { Shape s1; Shape s2 = Triangle(); cout << s1.toString() << s2.toString() << endl; } Triangle ShapeShape ShapeTriangle Compiles but prints something else

ShapeShape

[2523] What prints when this code is run? #include <string> #include <iostream> using namespace std; class Shape { public: 🌺string toString() const { return "Shape"; } }; class Circle : public Shape { public: string toString() const { return "Circle"; } }; class Triangle : public Shape { public: string toString() const { return "Triangle"; } }; int main() { Shape* s1 = new Circle; Shape* s2 = new Triangle; cout << s1->toString() << s2->toString() << endl; } ShapeShape ShapeTriangle CircleTriangle Does not compile

ShapeShape

[2524] What prints when this code is run? #include <string> #include <iostream> using namespace std; class Shape { public: 🌺string toString() const { return "Shape"; } }; class Circle : public Shape { public: virtual string toString() const { return "Circle"; } }; class Triangle : public Shape { public: virtual string toString() const { return "Triangle"; } }; int main() { Shape* s1 = new Circle; Shape* s2 = new Triangle; cout << s1->toString() << s2->toString() << endl; } ShapeShape ShapeTriangle CircleTriangle Does not compile

ShapeShape

[2533] What prints when this code is run? #include <string> #include <iostream> using namespace std; class Shape { public: virtual void iam() const; }; class Square : public Shape { }; class Oval: public Shape { public: void iam() const; }; void Shape::iam() const { cout << "Shape"; } void Oval::iam() const { cout << "Oval"; } void iam(const Shape* s) { s->iam(); } int main() { Shape *a = new Shape, *b = new Square, *c = new Oval; iam(a); iam(b); iam(c); } ShapeShapeOval ShapeSquareOval ShapeShapeShape ShapeSquareShape

ShapeShapeOval

[2528] What prints when this code is run? #include <string> #include <iostream> using namespace std; class Shape { public: virtual void iam() const; }; class Square : public Shape { public: void iam() const; }; class Oval: public Shape { public: void iam() const; }; void Shape::iam() const { cout << "Shape"; } void Square::iam() const { cout << "Square"; } void Oval::iam() const { cout << "Oval"; } void iam(Shape s) { s.iam(); } 🌺 int main() { iam(Shape()); iam(Square()); iam(Oval()); cout << endl; } ShapeSquareShape ShapeSquareOval ShapeShapeOval ShapeShapeShape Does not compile

ShapeShapeShape

[2531] What prints when this code is run? #include <string> #include <iostream> using namespace std; class Shape { public: virtual void iam() const; }; class Square : public Shape { public: void iam() const; }; class Oval: public Shape { public: void iam() const; }; void Shape::iam() const { cout << "Shape"; } void Square::iam() const { cout << "Square"; } void Oval::iam() const { cout << "Oval"; } void iam(const Shape& s) { s.iam(); } int main() { Shape a = Shape(), b = Square(), c = Oval(); ..// Slices iam(a); iam(b); iam(c); } ShapeShapeOval ShapeSquareOval ShapeShapeShape ShapeSquareShape

ShapeShapeShape

[2536] What prints when this code is run? #include <string> #include <iostream> #include <vector> using namespace std; class Shape { public: virtual void iam() const; }; class Square : public Shape { public: void iam() const; }; class Oval: public Shape { public: void iam() const; }; void Shape::iam() const { cout << "Shape"; } void Square::iam() const { cout << "Square"; } void Oval::iam() const { cout << "Oval"; } void iam(const Shape& s) { s.iam(); } int main() { vector<Shape🌺> v = {Shape(), Square(), Oval()}; for (auto& e : v) iam(e); cout << endl; } ShapeShapeOval ShapeSquareOval ShapeShapeShape ShapeSquareShape Does not compile

ShapeShapeShape

[2529] What prints when this code is run? #include <string> #include <iostream> using namespace std; class Shape { public: virtual void iam() const; }; class Square : public Shape { public: void iam() const; }; class Oval: public Shape { public: void iam() const; }; void Shape::iam() const { cout << "Shape"; } void Square::iam() const { cout << "Square"; } void Oval::iam() const { cout << "Oval"; } void iam(const Shape& s) { s.iam(); } 🌺 int main() { iam(Shape()); iam(Square()); iam(Oval()); cout << endl; } ShapeShapeOval ShapeSquareOval ShapeShapeShape ShapeSquareShape

ShapeSquareOval

[2530] What prints when this code is run? #include <string> #include <iostream> using namespace std; class Shape { public: virtual void iam() const; }; class Square : public Shape { public: void iam() const; }; class Oval: public Shape { public: void iam() const; }; void Shape::iam() const { cout << "Shape"; } void Square::iam() const { cout << "Square"; } void Oval::iam() const { cout << "Oval"; } void iam(const Shape& s) { s.iam(); } 🌺 int main() { iam(Shape()); iam(Square()); iam(Oval()); cout << endl; } ShapeShapeOval ShapeSquareOval ShapeShapeShape ShapeSquareShape

ShapeSquareOval

[2535] What prints when this code is run? #include <string> #include <iostream> #include <vector> using namespace std; class Shape { public: virtual void iam() const; }; class Square : public Shape { public: void iam() const; }; class Oval: public Shape { public: void iam() const; }; void Shape::iam() const { cout << "Shape"; } void Square::iam() const { cout << "Square"; } void Oval::iam() const { cout << "Oval"; } void iam(const Shape* s) { s->iam(); } int main() { vector<Shape*🌺> v = {new Shape, new Square, new Oval}; for (auto& e : v) iam(e); cout << endl; } ShapeShapeOval ShapeSquareOval ShapeShapeShape ShapeSquareShape Does not compile

ShapeSquareOval

[2537] What prints when this code is run? #include <string> #include <iostream> using namespace std; class Shape { public: virtual void iam() const; }; class Square : public Shape { public: void iam() const; }; class Oval: public Shape { public: void iamm() const; }; 🌺 void Shape::iam() const { cout << "Shape"; } void Square::iam() const { cout << "Square"; } void Oval::iamm() const { cout << "Oval"; } void iam(const Shape* s) { s->iam(); } int main() { Shape *a = new Shape, *b = new Square, *c = new Oval; iam(a); iam(b); iam(c); } ShapeShapeOval ShapeSquareOval Does not compile ShapeShapeShape ShapeSquareShape

ShapeSquareShape

[2525] What prints when this code is run? #include <string> #include <iostream> using namespace std; class Shape { public: virtual string toString() const { return "Shape"; } }; class Circle : public Shape { public: virtual string toString() const { return "Circle"; } }; class Triangle : public Shape { public: virtual string toString() const { return "Triangle"; } }; int main() { Shape s1 = Circle(); Shape* s2 = new Triangle; cout << s1.toString() << s2->toString() << endl; } ShapeShape ShapeTriangle CircleTriangle Compiles but prints something else

ShapeTriangle

defining

Specifying the calculation or actions that occur when the function is used

declaring

Specifying the function name, type and parameter types.

[2429] What is the output? class Car { public: virtual void setSpeed(double s) { speed = s; } double getSpeed() const { return speed; } private: double speed = 0; }; class AeroCar : public Car { public: void setSpeed(double s) { Car::setSpeed(10 * s); } void addSpeed(double s) { Car::setSpeed(getSpeed() + s); } }; int main() { AeroCar ac1; ac1.setSpeed(10); ac1.addSpeed(250); cout << "Speed: " << ac1.getSpeed(); } Speed: 260 Speed: 350 Speed: 250 Speed: 420

Speed: 350

[2440] What prints here? class Car { public: Car() = default; Car(double s): speed(s) {} double getSpeed() const { return speed; } private: double speed = 0; }; class AeroCar : public Car { public: AeroCar() = default; AeroCar(double h, double s) : Car(s * 2), height(h) {} void display() const; private: double height = 0; }; void AeroCar::display() const { cout << "Speed: " << getSpeed() << "; Height: " << height << endl; } int main() { AeroCar acar1(2000, 200); acar1.display(); } Speed: 400; Height: 2000 Speed: 0; Height: 2000 Speed: 200; Height: 2000 Speed: 0; Height: 0

Speed: 400; Height: 2000

[1341] Which area of memory are local variables stored in?

Stack

[2102] The ___________ of an object consist of its attributes or characteristics, represented by the values stored in its data members. Identity State Class Behavior Object

State

[1342] Which area of memory are global variables stored in?

Static storage area

[1909] The variable *p: void f( ) { string *p = new string; } ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ It's undefined → Code does not compile Stores an empty string Stores nullptr It's uninitialized Stores a memory address ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Stores an empty string

[1907] The variable *p: void f( ) { int *p = new int{}; } ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Stores a memory address It's uninitialized Stores the value 0 in all versions of C++ Stores the value 0 in C++11 only It's undefined → Code does not compile. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Stores the value 0 in C++11 only

[1905] The variable *p: void f( ) { int *p = new int{42}; } ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ It's undefined → Code does not compile Stores a memory address Stores the value 42 in all versions of C++ Stores the value 42 in C++11 only It's uninitialized ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Stores the value 42 in C++11 only

[1906] The variable *p: void f( ) { int *p = new int(42); } ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ It's undefined → Code does not compile. Stores the value 42 in all versions of C++ Stores a memory address It's uninitialized Stores the value 42 in C++11 only ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Stores the value 42 in all versions of C++

[2101] Which of these is not a property of an object (in the OOP sense)? Substitutablility Identity State All of these are properties of an object Behavior

Substitutablility

[1413] What does this loop do? int a[] = {6, 1, 9, 5, 1, 2, 3}; int x(0); for (auto e : a) x += e; cout << x << endl; Counts the elements in a Selects the largest value in a Has no effect Selects the smallest value in a Sums the elements in a

Sums the elements in a

What does this code do? int x = 0; vector<int> v{1, 3, 2}; for (auto e : v) x += e; cout << x << endl;

Sums the elements in v Prints 6

What kind of error is this? ex1.cpp:7:10: error: expected ';' after expression a = 4 ^ ;

Syntax error (mistake in grammar)

What kind of error is this? ex1.cpp:7:9: warning: missing terminating '"' character a = "hello world'; ^ ex1.cpp:7:9: error: expected expression

Syntax error (mistake in grammar)

Syntax error: ambiguous

Syntax error: no candidates

[1410] What does the array a contain after this runs? int a[] = {1, 2, 3}; int b[] = {4, 5, 6}; a = b; Syntax error; does not compile. {4, 5, 6} {1, 2, 3} Undefined behavior

Syntax error; does not compile.

Suppose you have written a program that inputs data from a file. If the input file does not exist when the program executes, then you should choose which option?

Terminate the program.

[1340] Which area of memory is your program code stored in?

Text

[2519] Below is a class hierarchy. Which statements may result in slicing? class Widget { . . . }; class Label: public Widget { . . . }; class Button: public Widget { . . . }; class Text: public Widget { . . . }; class TextArea: public Text { . . . }; class TextLine: public Text { . . . }; class Container: public Widget { . . . }; class Canvas: public Container { . . . }; class Window: public Container { . . . }; Text p = TextLine(); Widget p = Widget(); Widget* p = new TextArea; Container& p = *(new Window);

Text p = TextLine();

[2428] AeroCar is derived from Car. What must be done for AeroCar to override the setSpeed function? class Car { public: Car(); virtual void setSpeed(double newSpeed); double getSpeed() const; private: double speed; }; The AeroCar class must define the function void override(string setSpeed, double newSpeed); The AeroCar class must define the function void overrideSetSpeed(double) The AeroCar class must define the function void setSpeed(double) The AeroCar class cannot override the setSpeed member function.

The AeroCar class must define the function void setSpeed(double)

[2424] Suppose that we have a function that registers a Vehicle object. We also have a Car object that is a specialized Vehicle (defined by inheritance). The substitution principle states ___________. The Car object can never be used in any function that is written to use a Vehicle object. A new registration function that is written to use a Car object can be used in place of the Vehicle registration function The Car object can be used in the Vehicle registration function because it is a kind of Vehicle The Vehicle object can always be used wherever a Car object is expected

The Car object can be used in the Vehicle registration function because it is a kind of Vehicle.

[2433] Based on the following declaration of the Employee class where Manager is derived from Employee, which of the following are true? class Employee { public: Employee(); Employee(const string&); Employee(double); Employee(const string&, double); void setName(const string&); string getName()const; private: string name; double salary; }; The Manager class does not inherit the private data members The Manager class inherits name and salary, but Manager functions can only change the values of the name data member A Manager object has direct access to the name and salary inherited data members The Manager class inherits name and salary, but Manager functions cannot change the values of either data member.

The Manager class inherits name and salary, but Manager functions can only change the values of the name data member

[2235] The Point class represents x,y coordinates in a Cartesian plane. What is the mistake in this operator? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } }; ostream& operator<<(ostream& out, Point& p) { return out << '(' << p.x() << ", " << p.y() << ')'; } The data members x_ and y_ are inaccessible in a non-member function. There is no error; it works fine. The Point p parameter should be const Does not compile; should be a member function. You must first write to out and then return it.

The Point p parameter should be const

[2503] Below is a class hierarchy for card games. What happens when showScore() is called? class Hand { std::vector<Card> cards; public: void add(const Card&); Card get(size_t index) const; virtual int score() const; }; class PokerHand : public Hand { . . . }; class BlackjackHand : public Hand { . . . }; class GoFishHand : public Hand { . . . }; void showScore(const Hand h 🌺) { cout << h.score() << endl; } . . . PokerHand ph; . . . showScore(ph 🌺); // what happens here? The PokerHand portion of ph is sliced off and it becomes a Hand object It does not compile because ph is not a Hand object so we have a type error It does not compile because you should pass &ph instead of ph The Hand object is converted to a PokerHand object implicitly It prints the score for the PokerHand object named ph

The PokerHand portion of ph is sliced off and it becomes a Hand object

[2434] The Car class inherits from the Vehicle class. The Car class contains one constructor which does not call a particular Vehicle constructor. Which of the following is true? Vehicle constructors can never be called by the Car constructors The Car class will not compile because it does not explicitly call a Vehicle constructor The Vehicle default constructor is implicitly called by the Car constructor All Vehicle constructors are implicitly called by the Car constructor.

The Vehicle default constructor is implicitly called by the Car constructor

[1332] What is printed when you run this code? int *n{nullptr}; cout << n << endl;

The address value 0

[1334] What is printed when you run this code? int *n{nullptr}; cout << &n << endl;

The address value where n is stored

[1622] Below is endsWith(), a template function that works with two partially-filled arrays. The function returns true if the array a "ends with" the same elements as the array b, false otherwise. The function contains an error; what is the error? template <typename T> bool endsWith(T** a, size_t sizeA, T** b, size_t sizeB) { if (sizeA < sizeB) return false; size_t diff = sizeA - sizeB; for (size_t i = 0; i < sizeB; i++) if (a[i + diff] != b[i]) return false; return true; } The arrays a and b should be const T* sizeA and sizeB should both be passed by reference The condition (sizeA < sizeB) should be (sizeA > sizeB) The condition a[i + diff] != b[i] should be a[i - diff] == b[i]

The arrays a and b should be const T*

[2443] The Manager class is derived from the Employee base class. The Manager class overrides the getSalary()function. What is wrong with the following definition of getSalary() in the Manager class? double Manager::getSalary() const { auto baseSalary = getSalary(); return baseSalary + bonus; } The call to getSalary should be written as this->getSalary(); The call to getSalary should be written as Employee::getSalary(); The Manager class cannot call the getSalary() function in the base class The initialization of baseSalary should have been auto baseSalary = Employee::salary;

The call to getSalary should be written as Employee::getSalary();

[1621] Below is startsWith(), a template function that works with two partially-filled arrays. The function returns true if the array a "starts with" the same elements as the array b, false otherwise. The function contains an error; what is the error? template <typename T> bool startsWith(const T** a, size_t sizeA, const T** b, size_t sizeB) { if (sizeA > sizeB) return false; for (size_t i = 0; i < sizeB; i++) if (a[i] != b[i]) return false; return true; } The condition i < sizeB should be i <= sizeB The condition a[i] != b[i] should be b[i] == a[i] sizeA and sizeB should both be passed by reference The condition (sizeA > sizeB) should be (sizeB > sizeA)

The condition (sizeA > sizeB) should be (sizeB > sizeA)

[2113] Which members often use the modifier explicit in their declaration? The copy constructor The conversion constructor The default constructor None of these The working constructor

The conversion constructor

[2021] Which of these are part of the implementation? class Time { public: Time(); long get() const; void set(long); private: long seconds; }; The accessor and the mutator The constructor The data member seconds All of these are part of the implementation None of these are part of the implementation

The data member seconds

[2233] The Point class represents x,y coordinates in a Cartesian plane. What is the mistake in this operator? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } }; ostream& operator<<(ostream& out, const Point& p) { return out << '(' << p.x_ << ", " << p.y_ << ')'; } ≔ The Point p parameter should not be const Does not compile; should be a member function There is no error; it works fine. You must return out after writing to it. This example returns void The data members x_ and y_ are inaccessible in a non-member function ≕

The data members x_ and y_ are inaccessible in a non-member function

[1911] The variable p points to: void f( ) { int *p = new int[42](); } ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ The first element of an array of 42 uninitialized ints The first element of an array of 42 ints with the value 0 A single int with the value 42 It's undefined → Code does not compile ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

The first element of an array of 42 ints with the value 0

[1910] The variable p points to: void f( ) { int *p = new int[42]; } ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ It's undefined Code → does not compile The first element of an array of 42 uninitialized ints A single int with the value 42 The first element of an array of 42 ints with the value 0 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

The first element of an array of 42 uninitialized ints

[1329] What is printed when you run this code? int x(100); cout << &x << endl;

The memory location where x is stored

Examine the following code (which is legal). What changes are necessary to allow the statement if (m1 == m2) ... to compile? struct Money { int dollars{0}, cents{0}; } m1, m2; bool equals(const Money& lhs, const Money& rhs) { return lhs.cents == rhs.cents && lhs.dollars == rhs.dollars;

The name of equals() must be changed to operator==

[2228] The Point class represents x,y coordinates in a Cartesian plane. What is the mistake in this operator? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } Point operator+=(const Point& rhs) { . . . return *this; } }; ≔ The parameter should be a non-constant reference The operator should have const at the end of the header The operator return type should be a Point& The operator should end with return this, not return *this Does not compile; should be a non-member function ≕

The operator return type should be a Point&

[2231] The Point class represents x,y coordinates in a Cartesian plane. What is the mistake in this operator? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } Point& operator+=(const Point& rhs) { . . . } }; Point& operator+(const Point& lhs, const Point& rhs) { return Point(lhs) += rhs; } ≔ There is no error; it works fine. Does not compile; should be a member function The rhs parameter should not be const The operator should not change any of its parameters The operator return type should not be a Point&. ≕

The operator return type should not be a Point&.

[2229] The Point class represents x,y coordinates in a Cartesian plane. What is the mistake in this operator? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } Point& operator+=(const Point& rhs) { . . . } }; const Point operator+(Point& lhs, const Point& rhs) { return lhs += rhs; } The operator should not change any of its parameters There is no error; it works fine. Does not compile; should be a member function. The rhs parameter should not be const The operator should return lhs after adding rhs to it.

The operator should not change any of its parameters

[2227] The Point class represents x,y coordinates in a Cartesian plane. What is the mistake in this operator? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } Point& operator+=(Point& rhs) { . . . return *this; } }; Does not compile; should be a non-member function. The operator return type should be a const Point The parameter should be a constant reference The operator should end with return this, not return *this. The operator should have const at the end of the header

The parameter should be a constant reference

What is the problem here? make: *** No targets specified and no makefile found. Stop.

The programmer is in the wrong directory.

[1810] Which value of a is stored in the val variable? auto val = a[0][2]; The value in the first row and the third column The value in the third row and the first column The value in the first row and the second column None of these The value in the first row and the first column

The value in the first row and the third column

What is the output of the following? int i = 1; int sum = 0; while (i <= 13) { sum = sum + i; i = i + 3; } cout << "The value of sum is " << sum;

The value of sum is 35

What is the output of the following? int i = 1; int sum = 0; while (i <= 11) { sum = sum + i; i++; } cout << "The value of sum is " << sum;

The value of sum is 66

[1612] Below is pop(), a template function that works with a partially-filled array. The function copies the last element in the array into the output parameter e and returns true if successful; it returns false otherwise. What is the error? template <typename T> bool pop(T* a, size_t& size, T& e) { if (size) { e = a[size]; size--; return true; } return false; } a should be a const T* Condition should be !size size should be incremented The wrong value is assigned to e

The wrong value is assigned to e

[2230] The Point class represents x,y coordinates in a Cartesian plane. What is the mistake in this operator? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } Point& operator+=(const Point& rhs) { . . . } }; const Point operator+(const Point& lhs, const Point& rhs) { return Point(lhs) += rhs; } The operator should not change any of its parameters The operator return type should be a Point&. The rhs parameter should not be const Does not compile; should be a member function. There is no error; it works fine.

There is no error; it works fine.

[2232] The Point class represents x,y coordinates in a Cartesian plane. What is the mistake in this operator? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } }; ostream& operator<<(ostream& out, const Point& p) { return out << '(' << p.x() << ", " << p.y() << ')'; } ≔ There is no error; it works fine The Point p parameter should not be const Does not compile; should be a member function You must return out after writing to it. This example returns void The data members x_ and y_ are inaccessible in a non-member function ≕

There is no error; it works fine.

[2023] What is the semantic error in this class definition? class Time { long seconds; public: Time(); long get() const; void set(long); }; get() should not have const at the end seconds should be in the private section get() is missing an argument There is no semantic error. set() is missing const at the end

There is no semantic error.

What is true about identifiers in C++?

They may contain an underscore

A 2D array address expression is the equivalent of: *(address + (row * width + col))

True

A 2D array is a 1D array whose elements are also 1D arrays.

True

A behavior of an object is represented by the messages that it responds to.

True

A catch(...) will catch any kind of thrown exception

True

A class definition ends with a semicolon.

True

A class definition normally appears in a .h file.

True

A class is an interface paired with an implementation.

True

A class represents a template or blueprint for creating objects of a particular kind.

True

A class specifies the attributes of the objects it creates through the definition of internal data members.

True

A class specifies the behavior of the objects it creates through the definition of embedded functions, called member functions.

True

A completion code is a special return value that means "the function failed to execute correctly."

True

A constructor always has the same name as the class, and no return type.

True

A constructor is a member function whose job is to initialize an object into a well-formed state.

True

A constructor that takes a single argument of a different type is also known as a conversion constructor.

True

A constructor that takes a single argument of a different type may be called implicitly.

True

A do-while loop is also called a hasty loop.

True

A function that is marked with the keyword inline must be places in the header file.

True

A parameter with a default argument cannot appear before a parameter without a default argument.

True

A pointer that goes out of scope before deleting the memory it points to is called a memory leak.

True

A pointer-like object that can be used to automatically manage memory allocated on the heap is called a smart pointer.

True

A reference variable has the same identity as the variable it refers to.

True

A shared_ptr uses a reference count to manage how many pointers point to an object.

True

A template function may be defined in a header file.

True

A token is a "chunk of meaningful data".

True

A try block is a block of code where runtime or logical errors may occur

True

A unique_ptr can refer to a dynamic array.

True

A unique_ptr may transfer its ownership to another unique_ptr.

True

Accessor member functions are allowed to read data members, but not change them.

True

Accessor member functions should always end in the keyword const.

True

Although not possible in earlier versions of C++, in C++11 you can ask the compiler to retain the synthesized constructor when adding new ones.

True

An array passed to a function f(int *a, ...) may have its elements changed. An array passed to a function decays to a pointer. An array passed to a function f(int * const a, ...) may have its elements changed. The elements of an array may be allocated on the stack. If p points to the first element in [1, 3, 5] then cout << ++*p prints 2. The library function begin(a) returns a pointer to the first element in the array a. The elements of an array may be allocated in the static storage area. Arrays generally have higher performance than a vector. The function mystery(const int*, const int*) likely employs an iterator loop. The expression begin(a) + 1 returns a pointer to the second element in the array a. Array subscripts are not range checked An array passed to a function is passed by address. If size_t len = 0; then len - 1 is the largest possible unsigned number. If p points to the first element in [1, 3, 5] then cout << *++p prints 3. The algorithm that finds the address of the smallest element in an array is called an extreme values algorithm. The expression *p++ means the same as *(p++). Before passing an array to a function, sizeof(a)/sizeof(a[0]) will tell the number of elements in the array. For systems programming (such as operating systems), arrays are used more often than vectors. The library function end(a) returns a pointer to position right past the last element in the array a. For embedded systems, arrays are preferred over vector. The parameter declarations int *p and int p[] mean the same thing. The algorithm that prints elements separated by commas is called the fencepost algorithm. The elements of a vector are allocated on the heap. A vector variable may be allocated on the stack. Before passing an array to a function, sizeof(a) will tell you the array's allocated size, but not the number of elements.

True

An incomplete type and a forward reference generally mean the same thing. In C++ using == to compare one array to another is permitted (if meaningless). You must use an integral constant or literal to specify the size of a built-in C++ array. The reinterpret_cast instruction changes way that a pointer's indirect value is interpreted. If p is a pointer to a structure, and the structure contains a data member x, you can access the data member by using the notation: (*p).x C++ arrays have no support for bound-checking. In C++ assigning one array to another is illegal The allocated size of a built-in C++ array cannot be changed during runtime. The size of the array is not stored along with its elements. If img is a pointer to the first byte in an image loaded into memory, Pixel is a structure as defined in your textbook, you can create a Pixel pointer pointing to the image by writing: Pixel *p = reinterpret_cast<Pixel *>(img); The subscripts of a C++ array range from 0 to the array size - 1. C++ arrays have no built-in functions for inserting and deleting. A forward reference can be used when you want to use a pointer to a structure as a data member without first defining the entire structure. The elements of a C++ array created in a function are allocated on the stack. The elements of a C++ array created outside of a function are allocated in the static-storage area. The elements of a C++ string array with no explicit initialization, created in a function will be set to the empty string. Explicitly initializing an array like this: int a[3] = {1, 2, 3}; requires the size to be the same or larger than the number of elements supplied. In C++ printing an array name prints the address of the first element in the array. In C++ there is no separate array variable. The array name is a symbolic representation of the address of the first element in the array. In C++ initializing an array with the contents of another is illegal. C++ arrays produce undefined results if you access an element outside the array. Explicitly initializing an array like this: int a[] = {1, 2, 3}; works in all versions of C++.

True

An object (in the OOP sense) is an instance of a particular class.

True

An overloaded operator must have at least one operand that is a user-defined type.

True

Arrays can have more than two dimensions in C++.

True

Assuming lastName is a string object, does this work as expected in C++? if (lastName <= "Gilbert") . . .

True

Assuming p is a pointer to a single variable allocated on the heap, the statement delete p; returns the allocated memory back to the operating system for reuse.

True

Assuming p is a pointer to the first variable in an array allocated on the heap, the statement delete[] p; returns the allocated memory back to the operating system for reuse.

True

Assuming str is a string object does this correctly test if str consists of the characters "quit" in C++? if (str == "quit") . . .

True

Assuming str is a string object, is this syntax legal in both Java and C++? if (str == "quit") . . .

True

Building your code with more than one copy of a function leads to a clash of symbols.

True

C++11 you can ask the compiler to retain the synthesized constructor when adding new ones.

True

Calling a function like to_string(3.5) is known as implicit instantiation

True

Calling cout.put("A") is illegal. Your code will not compile.

True

Calling cout.put(c) converts its argument, c, to a character.

True

Calling exit() terminates a program immediately and passes an error code back to the operating system.

True

Calling s.at(0) returns the same reference as s.front().

True

Classes whose objects need to be sorted should overload == and !=.

True

Command line arguments that start with a hyphen are usually called switches.

True

Conceptually, a 2D array is rectangular grid of columns and rows.

True

Constructors always have the same name as the class and no return type.

True

Constructors are called implicitly whenever an object is created.

True

Creating objects from a class is called instantiation.

True

Encapsulation enforces the principle of data hiding.

True

Freeing unused memory that was allocated elsewhere in your program is done in C++ using manual memory management.

True

Functions with generic parameters are known as function templates.

True

If a member function is in the private section of a class, it can only be called by other member functions of the class.

True

If no exception is thrown in a try block, all catch blocks associated with that try block are ignored.

True

If the new operator cannot allocate memory, C++ throws an exception.

True

If you do not create a constructor for your class, C++ will synthesize a default constructor for you.

True

If you write a working constructor for your class, C++ will remove the synthesized default constructor.

True

If your class does not have a constructor, the compiler will synthesize a default constructor for you.

True

In C++ the only difference between structures and classes is that member functions are private by default in classes.

True

In C++ the only difference between structures and classes is that member functions are public by default in structures.

True

In C++ you can concatenate string objects using the + or += operators.

True

In C++ you use the keyword public or private to create a section that indicates the access privileges of subsequent data members or member functions.

True

In a 2D array the first subscript represents the rows and the second the columns.

True

In a constructor, initializing data members by using the assignment operator means that those objects may be initialized twice.

True

In a constructor, objects can be initialized immediately before the opening brace of the constructor, before any other code has been run.

True

In a do-while loop, (condition) is followed by a semicolon.

True

Inheritance allows you to build a new class by using an existing class as a starting point.

True

Initialization of data members occurs according to the order they are listed in the class definition.

True

Marking a constructor with the explicit keyword, prevents unintended conversions.

True

Member functions that initialize the data members of a new object are called constructors.

True

Member operators have direct access to private data members.

True

Memory for global variables is allocated when the program is loaded from disk. This is known as static allocation.

True

Mutator member functions are allowed to read data members and also change them.

True

Non-member operators have direct access to private data members.

True

Object behavior is implemented by member functions.

True

Objects are variables of programmer-defined types.

True

On the command line, argc is the count of arguments including the program itself.

True

One of the main problems with the completion code strategy of error handling is that callers can ignore the return value without encountering any warnings

True

Overloaded operators are functions that use special names that begin with the keyword operator.

True

Overloaded operators may be implemented as member functions.

True

Overloaded operators may be implemented as non-member functions.

True

Physically, a 2D array is stored as a single linear, contiguous array with the elements for each row following the elements for the previous row in memory.

True

Polymorphism means that different objects (of different types) can respond to the same message in different ways.

True

Polymorphism only works in the presence of inheritance.

True

Programmers using structure-derived variables, directly manipulate the data members of those variables.

True

Requesting a block of memory from the operating system as the program runs is known as dynamic allocation.

True

Side-effect operators, such as increment or short-hand assignment, should be written as member operators.

True

Smart pointers automatically delete the memory they point to at the appropriate time.

True

Suppose you have two classes related by inheritance: Dog and Poodle. According to the rules of inheritance, Poodle is a specialization of Dog.

True

Symetric operators, where the user-defined type may appear on the left or the right, should be written as non-member operators.

True

The I/O operators must always be written as non-member operators.

True

The arithmetic operators, such as addition, subtraction and multiplication for type T should return a const T.

True

The attributes of an object refers to the names and types of its data members.

True

The compiler determines which overloaded function to call by looking at the number, types and order of the arguments passed to the function.

True

The constructor initializer list follows the parameter list and precedes the constructor body.

True

The constructor that is used to initialize all of an object's fields is called the working constructor.

True

The constructor that takes no arguments is called the default constructor.

True

The expression *this can only be returned from member operators.

True

The expression *this is called a self-reference.

True

The implementation of a class includes all private data members in the header file.

True

The implementation of a class normally appears partly inside the class .cpp file and partly inside the class .h file.

True

The implementation of a member function from the Time class would look something like this: int Time::hours() const {...}

True

The interface of a class includes all public items in the header file.

True

The keywords public and private are the C++ mechanism for defining interfaces and enforcing encapsulation Member functions that change the state of an object are called mutators A constructor that takes no arguments is called the default constructor Using classes for user-defined types means that you can enforce restrictions on data member access Accessor member functions are allowed to read data members and also change them

True

The member function int hours() const; provides read-only access to the hours property (however it is stored).

True

The member function int& hours(); provides read-write access to the hours property (however it is stored).

True

The parameter names lhs and rhs are commonly used with overloaded operators.

True

The predefined constant __cpluplus indicates which version of the C++ standard is being used

True

The private inheritance relationship is informally known as implemented-with The public inheritance relationship is informally known as is-a The composition relationship is informally known as has-a The keyword override allows the compiler to ensure that the base-class function you are overriding is virtual Non-virtual functions always use early, or compile-time binding to decide which function to call Creating a new class by combining instances of simpler classes as data members is called composition It is always a logic error for a derived class to redefine a non-virtual function Putting the keyword final at the end of the class heading prohibits the creation of subsequent derived classes Waiting until runtime to determine which function to call is known as late binding Waiting until runtime to determine which function to call is known as dynamic dispatch Virtual functions invoked through a pointer to a base-class object use late binding to decide which function to call If a virtual member function does not use the keyword final, then any derived class may override that function In private inheritance derived classes inherit the implementation of the base class, but not its interface Virtual functions invoked through a reference to a base-class object use late binding to decide which function to call Virtual member functions are implemented by adding a new pointer to every object that contains at least one virtual function In private inheritance a using declaration is employed to selectively bring base class members into the derived class scope Tell the compiler that you intend to override a base class function by adding the keyword override to the end of the member function declaration Putting the keyword final at the end of a virtual member function heading prohibits derived classes from overriding that function

True

The prototype for a member addition operator for the type T is: const T operator+(const T& rhs) const;

True

The prototype for a non-member subtraction operator for the type T is: const T operator-(const T& lhs, const T& rhs);

True

The public interface of a class consists of the prototypes of its member functions.

True

The release() function returns the raw pointer that a unique_ptr contains before seting the pointer to nullptr.

True

The rules for partial initialization of a 2D array can be changed by adding braces around interior array elements.

True

The short-hand assignment operators for type T should return *this.

True

The short-hand assignment operators for type T should return a T&.

True

The signature for the postfix decrement operator (of type T) is: const T operator--(int);

True

The state of an object refers to the combination of values stored in its data members.

True

The statement new int; allocates an uninitialized integer on the heap.

True

The statement new int[3] = {1, 2, 3}; is a syntax error.

True

The statement new int[3](); allocates an array of three default-initialized integers on the heap.

True

The statement new int[3]; allocates an array of three uninitialized integers on the heap.

True

The statement new int[3]{1, 2, 3}; allocates an array of three initialized integers on the heap.

True

The statement new int{3}; allocates a single initialized integer on the heap.

True

The statement new int{}; allocates a default-initialized integer on the heap.

True

The strncat() function is tricky to use correctly. You can compare two C-strings, s1 and s2, by using the strcmp() function. C-strings are character arrays that rely on a special embedded sentinel value, the character with the ASCII code 0. The allocated size for the C-string char s1[] = "hello"; is 6 characters, while the effective size is 5 characters. The sizeof operator returns the allocated size of a C-string allocated as an array. The effective size of the C-string char * s1 = "hello"; is 5 characters, but 6 characters are used for storage. strcmp(s1, s2) returns a positive number if s1 is lexicographically "greater than" s2. C-strings use the strcat() function for concatenation. The strlen() function returns the effective size of a C-string. C-strings are often needed to interoperate with legacy C libraries. When writing programs that interact with your operating system facilities, either Windows, Mac OSX or Linux, you will normally use C-strings instead of the C++ library string type. The characters for the C-string char s1[] = "hello"; are stored in user memory and may be modified. C-strings are char pointers to the first character in a sequence of characters, terminated with a '\0' character. C-string functions may be more efficient than C++ string member functions. strcmp(s1, s2) returns a negative number if s1 is lexicographically "less than" s2. Given the C-string char * s3 = "hello"; strlen(s3) returns 5. C-string assignment uses the strcpy() function. strcmp(s1, s2) returns 0 if s1 and s2 contain the same characters. The C-string type is built into the C++ language, not defined in the standard library. The strcpy() function always appends a trailing NUL when the copy is finished. The strncpy() function can be used to make sure that you don't copy more characters than necessary. Programs written for embedded devices often use C-strings rather than the C++ library string type. The length of a C-string is never stored explicitly The C-string literal "cat" contains 4 characters. The strncat() function allows you to limit the maximum number of characters that are concatenated. The character with the ASCII code 0 is called the NUL character

True

The subscript operators must be written as a member operator.

True

The two parts of a class are a public interface and a private implementation.

True

Though not required, you should use the ordinary meaning of an operator when you overload it. It would be unwise to redefine subtraction to mean addition, for instance.

True

To allocate memory on the heap, C++ uses the new operator.

True

To ask a particular object to perform a particular action, you send your request by calling a member function.

True

To compare objects for equality, overload both == and !=.

True

To read a line of text, you include the header file <string>

True

To transfer a unique_ptr to a vector, use push_back along with the move() function.

True

To use different versions of a function depending on the platform is called conditional compilation.

True

Using a pointer to access the memory it points to after the pointer has been deleted is called a dangling pointer.

True

Using classes for user-defined types means that you can change the data representation without affecting the users of your class.

True

Using structures for user-defined types means that you cannot change the data representation without affecting the users of your data type.

True

Using structures for user-defined types means that you cannot enforce restrictions on data member access.

True

Variables tested with the #if preprocessor directive are created using #define

True

When a stream is converted to a Boolean condition, its fail() member function is implicitly called

True

When calling a member function, like t.hours(3); the address of the object t is passed to the function implicitly as the first parameter.

True

When inserting a value into a partially-filled array, in ascending order, the insertion position is the index of the first value larger than the value. When inserting a value into a partially-filled array, in ascending order, the insertion position may be the same as size. When inserting a value into a partially-filled array, in descending order, the insertion position is the index of the first value smaller than the value. When removing an element from a partially-filled array, elements following the deletion position are shifted to the left. When deleting elements from a partially-filled array, the array should not be declared const. In a partially-filled array size represents the number of elements that are in use. When inserting a value into a partially-filled array, elements following the insertion position are shifted to the right. In a partially-filled array, the capacity represents the allocated size of the array. When searching for the index of a particular value in a partially-filled array, the array should be declared const. When inserting an element into a partially-filled array, it is an error if size >= capacity. In a partially-filled array, the size may be less than the array's capacity. When comparing two partially-filled arrays for equality, both arrays should be declared const. When deleting an element from a partially-filled array, it is an error if the index of the element to be removed is >= size. In a partially-filled array, the size represents the effective size of the array. When inserting elements into a partially-filled array, the array should not be declared const.

True

When not using encapsulation, such with structures, changing the implementation of the structure changes the interface as well.

True

When not using encapsulation, such with structures, you risk accidental data corruption.

True

When passing a 2D array to a function, the array parameter must explicitly list the size for all dimensions except for the first, like: void f(int a[][3], size_t n);

True

When using the get() member function, a stream will fail only if there are no characters left in the input stream.

True

When you throw an exception, control immediately jumps out of the current try block.

True

With classes, the public interface includes the member functions that allow clients to access object data in a safe way.

True

With encapsulation, data and behavior are combined into a single object.

True

With inheritance, a family of related classes is called a class hierarchy.

True

With inheritance, the class you build upon is called a base class in C++.

True

With inheritance, the new class you create is called a derived class in C++.

True

Without try and catch, the throw statement terminates the running program

True

You can create vector objects to store any type of data, but each element in the vector must be the same type. Assume vector<int> v; Writing cout << v.front(); throws a runtime exception. Assume the vector v contains [1, 2, 3]. v.erase(v.begin() + 2); changes v to [1, 2]. The declaration: vector<string> v(5, "bob"); creates a vector containing five string objects, each containing "bob". In the declaration: vector<int> v; the word int represents the object's base type. The elements of a vector are allocated contiguously. vector subscripts begin at 0 and go up to the vector size - 1 The clear() member function removes all the elements from a vector. The statement v.insert(v.end() + 1, 3) is undefined because end() + 1 points past the last element in the vector. The statement v.insert(v.end(), 3) appends the element 3 to the end of the vector v. Contiguous allocation means that the elements are stored next to each other in memory. The push_back member function adds elements to the end of a vector. Assume the vector v contains [1, 2, 3]. v.erase(v.begin()); changes v to [2, 3]. The declaration: vector<int> v(10); creates a vector object containing ten elements initialized to 0. Assume the vector v contains [1, 2, 3]. v.pop_back(); changes v to [1, 2]. The term for classes with a base-type specification are parameterized classes. Assume that v contains [1, 2, 3]. The result of writing cout << v[4]; is undefined. The C++ term for classes like vector are template classes. A vector subscript represents the element's offset from the beginning of the vector. The declaration: vector<string> v{"bill", "bob", "sally"}; creates a vector containing three string objects. The declaration: vector<int> v(10, 5); creates a vector object containing ten integers. Assuming that Star is a structure, the declaration: vector<Star> stars(3); creates three default initialized Star objects. The declaration: vector<string> v(5); creates a vector containing five empty string objects. Assume the vector v contains [1, 2, 3]. v.erase(0); is a syntax error. The declaration: vector<int> v; creates a vector object with no elements. A vector represents a linear homogeneous collection of data. Assume vector<double> v; Writing cout << v.back(); is undefined. Elements in a vector are accessed using a subscript. Assume that v contains [1, 2, 3]. The result of writing cout << v.at(4); throws a runtime exception. The statement v.insert(v.begin(), 3) inserts the element 3 into the vector v, shifting the existing elements to the right.

True

You can only overload existing operators. You cannot use other symbols.

True

You can pass the 2D array int a[3][3] to the function f(int *a, size_t r, size_t c) by calling f(&a[0][0], 3, 3).

True

You can pass the 2D array int a[3][3] to the function f(int a[][3], size_t n) by calling f(a, 3).

True

You can pass the first row of the 2D array int a[3][3] to the function f(int *a, size_t n) by calling f(a[0], 3).

True

You can use a range-based loop on a 2D array.

True

You compiler or contains constants that can be used to identify the platform you are compiling on

True

You may add = default; to the prototype for a default constructor to retain the synthesized version in the presence of other overloaded constructors.

True

You may create a reference to a class that is abstract It is illegal to construct an instance of an abstract class Abstract classes specify a set of responsibilities that derived classes must fulfill The iostream class in the C++ standard library uses multiple inheritance In C++, an Abstract Base Class is any class that has one pure virtual member function An abstract class is a class that contains member functions that are specified but not implemented The C++ facility that allows a derived class to have multiple base classes is known as multiple inheritance In C++ pure virtual member functions may have an optional implementation Adding = 0 to the end of the heading of a virtual member function converts it to a pure virtual member function An abstract class requires its concrete derived classes to override all of its pure virtual (abstract) member functions In composition-based adapter classes, the member functions delegate or forward requests to the data member that can satisfy the request In C++, private inheritance can be used to create adapter classes Public inheritance models an IS-A relationship between classes Using public inheritance to derive Stack from vector is a problem because a Stack is really not a vector If a class is abstract, you may create a pointer of that class What Java calls an abstract method is called a pure virtual member function in C++ Consider the Shape class hierarchy, along with Circle, Square and Star from your text. The Shape class is an abstract base class

True

You may not overload the conditional operator ?:.

True

You may not overload the scope operator ::.

True

Your class may have more than one constructor.

True

Your operating system's command processor is known as the shell.

True

s.back() = 'x'; changes the last character in the string object s to 'x'.

True

This idiomatic pattern is used to count from one value to another. for (int i = 1; i <= 10; i++) cout << i; cout << endl; This idiomatic pattern is used to count from one value to another. for (int i = 1; i < 10; i++) cout << i; cout << endl;

True False

This loop uses asymmetric bounds. for (int i = 0; i < 10; i++) cout << i; cout << endl; This loop uses asymmetric bounds. for (int i = 1; i < 10; i++) cout << i; cout << endl; This loop uses asymmetric bounds. for (int i = 1; i <= 10; i++) cout << i; cout << endl;

True True False

When writing a function with stream parameters, always use the most general type of stream that meets the specification When writing a function with stream parameters, always use the most specific type of stream that meets the specification

True False

The C++ term for what is called a subclass in other languages is derived class The C++ term for what is called a subclass in other languages is base class

True False

The C++ term for what is called a superclass in other languages is base class The C++ term for what is called a superclass in other languages is derived class

True False

Unformatted I/O means that you read and write data character-by-character Unformatted I/O means that you read and write data line-by-line

True False

A tool named Doxygen is often used to generate HTML user docs from C++ code. If a prototype in a header file has a parameter that is a library type, the header file must #include the appropriate library header.

True True

A loop that reads data until some special value is found is called a sentinel loop. A loop that reads data until some special value is found is called a data loop.

True False

A loop that reads data until the input stream signals that it is done is called a data loop A loop that reads data until the input stream signals that it is done is called a sentinel loop

True False

A process filter does something to the characters it encounters A process filter learns something about the stream by examining characters

True False

A specialized error handling block of code, is called a catch block A specialized error handling block of code, is called a try block

True False

A state filter learns something about the stream by examining characters A state filter does something to the characters it encounters

True False

Counting the number of words in input by counting word transitions is an example of a state filter Counting the number of words in input by counting word transitions is an example of a process filter.

True False

Default arguments let you call a single function in several different ways. Default arguments allow you to write several different functions that have the same name.

True False

Formatted I/O means that you read and write data token-by-token Formatted I/O means that you read and write data line-by-line

True False

Function overloading allows you to write several different functions that have the same name. Function overloading lets you call a single function in several different ways.

True False

Functions with generic parameters may use the keyword class or the keyword typename for their type parameters Functions with generic parameters may use the keyword class or the keyword struct for their type parameters

True False

In C++ you can compare strings using all of the relational operators. In C++ you cannot use the relational or equality operators with strings.

True False

Overloaded functions have the same name but different parameter types. Overloaded functions have the same name but different parameter names.

True False

Stream parameters should always be passed to functions by reference Stream parameters should always be passed to functions by const reference

True False

The directives #if defined(symbol) and #ifdef symbol mean, essentially, the same thing The directives #if defined(symbol) and #ifndef symbol mean, essentially, the same thing.

True False

The expression cin.get(ch) returns a reference to the input stream The expression cin.get(ch) returns the next character from input

True False

The standard library version of sqrt(-2) returns the not-a-number error code The standard library version of sqrt(-2) throws a runtime exception because there is no possible answer

True False

The standard library version of stoi("UB-40") throws a runtime exception because there is no viable conversion The standard library version of stoi("UB-40") returns the not-a-number error code.

True False

To use strings as a data stream source or sink, use the <sstream> header To use strings as a data stream source or sink, use the <stringstream> header

True False

When using cin >> ch; to read a character, leading whitespace is skipped. When using cin >> ch; to read a character, leading whitespace is not skipped.

True False

When using the get() member function to read a character, leading whitespace is not skipped When using the get() member function to read a character, leading whitespace is skipped.

True False

You can report a logical error encountered in your code by using the throw keyword You can report a syntax error encountered in your code by using the throw keyword

True False

You can test if an I/O operation succeeded by explicitly calling the stream's fail() member function To test if an I/O operation succeeded you must explicitly call the stream's fail() member function

True False

s.at(0) = 'c'; changes the first character in the string object s to 'c' s.at(0) = "c"; changes the first character in the string object s to 'c'

True False

In the loop-and-a-half, you use a break statement to exit the loop when the sentinel is found In the loop-and-a-half, you use Boolean variable to signal when the sentinel is found In the loop-and-a-half pattern, you read data before the loop and at the end of the loop.

True False False

To use a disk file as a data stream source or sink, use the <fstream> header To use a disk file as a data stream source or sink, use the <ifstream> header To use a disk file as a data stream source or sink, use the <ofstream> header

True False False

A catch block may handle exception classes, as well as errors where int or string are thrown A catch block may only handle objects from classes derived from exception or logic_error A catch block specifies the type of exception it can catch and immediately terminates the program A catch block is a block of code where runtime or logical errors may occur

True False False False

If an input stream's file is missing when you try to open it, its fail() member function returns true If an input stream's file is missing when you try to open it, its fail() member function returns false If an output stream's file is missing when you try to open it, its fail() member function returns false.

True False True

The string find() member function may be used to search for a substring The string find() member function takes either a string or character as an argument The string find() member function throws an exception if the target cannot be found.

True True False

An unguarded loop is also known as a test-at-the-bottom loop. An unguarded loop is also known as a test-at-the-top loop.

True False

Calling s.at(1) returns a reference to the second character in the string object s Calling s.at(1) returns a copy of the second character in the string object s

True False

Default arguments appear only in the function prototype. Default arguments appear only in the function implementation.

True False

Implementation files may use the statement using namespace std; Implementation files must explicitly qualify each name from the standard library with std::

True False

In a guarded loop, the loop actions may never be executed In a guarded loop, the loop actions are always executed at least once.

True False

The #if preprocessor directive can compare integers The #if preprocessor directive may compare double literals but not variables

True False

The return value of the getline() function is an input stream object The return value of the getline() function is a string object.

True False

In the flag-controlled-pattern, you use Boolean variable to signal when the sentinel is found In the flag-controlled-pattern, you use a break statement to exit the loop when the sentinel is found. In the flag-controlled-pattern, you read data before the loop and at the end of the loop

True False False

In the primed loop pattern, you read data before the loop and at the end of the loop. In the primed loop pattern, you use Boolean flag to signal when the sentinel is found In the primed loop pattern, you use a break statement to exit the loop when the sentinel is found

True False False

The getline() function is a non-member function in the string library The getline() function is a member function in the string class The getline() function is a member function in the istream class.

True False False

Fatal error messages should be printed to cerr. Fatal error messages should be printed to cout.

True False

Loops are used to implement iteration in C++. Loops are used to implement selection in C++.

True False

Parameter names are optional in the function prototype Parameter names are optional in the function definition

True False

Strings in C++ are mutable. String in C++ are immutable

True False

The cin object is an instance of the istream class The cin object is an instance of the ifstream class

True False

The cout object is an instance of the ostream class. The cout object is an instance of the ofstream class

True False

Default arguments may only be used with value parameters. Default arguments may only be used with reference parameters. Default arguments may be used with both value and reference parameters.

True False False

Calling cout.put(65) prints the character 'A' on output Calling cout.put(65) prints the number 65 on output Calling cout.put(65) is illegal. Your code will not compile. Calling cout.put(65.35) is illegal. Your code will not compile

True False False False

An undefined error message is a linker error. An undefined error message is a compiler error

True ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ False

Header files must explicitly qualify each name from the standard library with std:: Header files may use the statement using namespace std;

True ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀ False

In an unguarded loop, the loop actions are always executed at least once. In an unguarded loop, the loop actions may never be executed.

True False

A guarded loop is also known as a test-at-the-top loop A guarded loop is also known as a test-at-the-bottom loop.

True False

What kind of error is this? ex1.cpp:6:12: error: no viable conversion from 'int' to 'string' string a = 15; ^ ~~

Type error (wrong initialization or assignment)

What prints here? double a = 1; switch (a) { case 1: cout << "1"; case 2: cout << "2"; } cout << endl;

Undefined behavior

[1709] What happens here? char s[] = "CS150"; strcat(s, "CS50"); cout << s << endl; Crashes when run Undefined behavior "CS50" "CS500" "CS150CS50"

Undefined behavior

[1714] What happens here? char s1[] = "CS150", s2[10]; strcpy(s1, s2); s2[0] = 'X'; cout << s1 << endl; "XS150" "CS150" Does not compile Crashes when run. Undefined behavior

Undefined behavior

[1933] What does this code print? int main() { auto p1 =unique_ptr<int>(new int{42}); cout << *p1; auto p2 = p1.release(); 🌺 cout << *p2; (*p2)++; cout << *p1; 🌺 Isn't called correctly } Does not compile (illegal) Undefined behavior 424242 424243 424343

Undefined behavior

[1535] What does this function do? double mystery(const double a[], size_t len) { double x = 0; for (size_t i = 0; i < len; i++) if (a[i] > x) x = a[i]; return x; } Undefined. Depends on the input. Does not compile Returns the largest number in the array Returns the smallest number in the array

Undefined. Depends on the input.

[1536] What does this function do? double mystery(const double a[], size_t len) { double x = 0; for (size_t i = 0; i < len; i++) if (a[i] < x) x = a[i]; return x; } Returns the largest number in the array Returns the smallest number in the array Undefined. Depends on the input. Does not compile

Undefined. Depends on the input.

[1328] What is a common pointer error?

Using a pointer without first initializing it

A set of bits interpreted according to its type

Value

arguments

Values passed to the function when it is invoked

parameters

Variables defined along with the function to receive input

[2425] The Department of Motor Vehicles uses a vehicle registration program that declares a Vehicle class as a base class. The Car class and the Truck class both inherit from the Vehicle class. Which types of objects can be passed to the function register(Vehicle& v)? It is impossible to know without examining the implementation of the Car and Truck classes Vehicle, Car and Truck objects Only Car and Truck objects Only Vehicle objects

Vehicle, Car and Truck objects

[2346] One remarkably simple formula for calculating the value of is the so-called Madhava-Leibniz series: Consider the recursive function below to calculate this formula: double computePI(int number) { if (number <= 1) { return 1.0;} int oddnum = 2 * number - 1; return computesign(number) * 1.0 / oddnum + computePI(number - 1); } In this recursive function, what is the recursive base case? When the parameter variable is less than or equal to one When the parameter variable is greater than one When the value that is returned from the function is zero When the parameter variable is zero

When the parameter variable is less than or equal to one

[1336] What is printed when you run this code? int n{}; int *p; *p = &n; cout << *p << endl;

Will not compile

[2518] Below is a class hierarchy. Which assignments are illegal? class Widget { . . . }; class Label: public Widget { . . . }; class Button: public Widget { . . . }; class Text: public Widget { . . . }; class TextArea: public Text { . . . }; class TextLine: public Text { . . . }; class Container: public Widget { . . . }; class Canvas: public Container { . . . }; class Window: public Container { . . . }; None of these are illegal Widget* p = new Canvas; Window* p = new Container; Text* p = new TextLine; Widget* p = new TextArea;

Window* p = new Container;

Append output to a file named z Discard both output and errors Write output to a new file named z Read the input from the file named z Write errors to a new file named z Send the output to the input of the program named z

X rm x > /dev/null/2>&1 X cat < z cat x 2>z date | z

Assume the user types "brown cow" when this code runs. What prints? int n; if (cin >> n) cout << "X\n"; else cout << "Y\n";

Y O U D O N O T N E E D T O R E V I E W F O R T R U E / F A L S E 🚨

[2342] In 1735 Leonard Euler proved a remarkable result, which was the solution to the Basel Problem, first posed in 1644 by Pietro Mengoli. This result gave a simple expression for mc042-1.jpg. The formula states that mc042-2.jpgis equal to the limit, as n goes to infinity, of the series mc042-3.jpg. Can this series be computed recursively? Yes, but the code will be very long No, because the base case is not zero Yes No, because there is no base case

Yes

[1723] Is p properly NUL-terminated when this function is called? void stringCopy(char **p, const char **q) { while ((**p = **q) != '\0') { p++; q++; } } No, because there is no *p = '\0'; after the loop No, because the comparison should be against 0, not against '\0' No, because the condition accidentally used = instead of == Yes, the terminator is copied as the condition fails No, because there is no actual copy of characters into p at all

Yes, the terminator is copied as the condition fails

[2036] There is no constructor for this class. class Integer { int value_ = 0; public: int get() const; int set(int n); }; You can create objects; value_ is initialized to 0 The code compiles, but you cannot create objects from this class You can create objects; value_ is uninitialized The code will not compile without a constructor

You can create objects; value_ is initialized to 0

[2037] There is no constructor for this class. class Integer { int value_; public: int get() const; int set(int n); }; You can create objects; value_ is initialized to 0 The code compiles, but you cannot create objects from this class You can create objects; value_ is uninitialized The code will not compile without a constructor

You can create objects; value_ is uninitialized

What is the problem here? You have submitted another student's completion code

You filled out the STUDENT variable incorrectly

In C++, what is true about the += operator operating on string objects

You may concatenate creates a string variable to a string object You may concatenate a string literal (character array) to a string object You may concatenate a char literal to a string object You may concatenate a char variable to a string object

[2234] The Point class represents x,y coordinates in a Cartesian plane. What is the mistake in this operator? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } }; void operator<<(ostream& out, const Point& p) { out << '(' << p.x() << ", " << p.y() << ')'; } Does not compile; should be a member function. The data members x_ and y_ are inaccessible in a non-member function. The Point p parameter should not be const You must return out after writing to it. This example returns void. There is no error; it works fine.

You must return out after writing to it. This example returns void.

Examine the following code (which is legal). What changes are necessary to allow the statement if (m1 != m2) ... to compile? struct Money { int dollars{0}, cents{0}; } m1, m2; bool equals(const Money& lhs, const Money& rhs) { return lhs.cents == rhs.cents && lhs.dollars == rhs.dollars; }

You must write a function named operator!=

[2112] What statement about constructors is false? All constructors are passed a pointer argument Constructors have no return type You must write at least one constructor for every class Constructors may take arguments Classes may have more than one constructor

You must write at least one constructor for every class

What is stored in data after this runs? vector<int> data{1, 2, 3}; data.push_back(0);

[1, 2, 3, 0]

[1540] What is printed? template <typename T> ostream& mystery(ostream& out, const T* p, size_t n) { out << '['; if (n) { out << p[0]; for (size_t i = 1; i < n; i++) out << ", " << p[i]; } out << "]"; return out; } . . . int a[] = {1,2,3,4,5,1}; mystery(cout, a, sizeof(a) / sizeof(a[0])) << endl; None of these or undefined output. [1, 2, 3, 4] [1, 2, 3] [1, 2, 3, 4, 5] [1, 2, 3, 4, 5, 1]

[1, 2, 3, 4, 5, 1]

[1538] What is printed? template <typename T> ostream& mystery(ostream& out, const T* p, size_t n) { out << '['; if (n) { out << p[0]; for (size_t i = 1; i < n; i++) out << ", " << p[i]; } out << "]"; return out; } int a[] = {1,2,3,4,5,1}; mystery(cout, a, 4) << endl; [1, 2, 3] [1, 2, 3, 4, 5, 1] None of these or undefined output. [1, 2, 3, 4, 5] [1, 2, 3, 4]

[1, 2, 3, 4]

What is stored in data after this runs? vector<int> data{1, 2, 3}; data.back();

[1, 2, 3]

What is stored in data after this runs? vector<int> data{1, 2, 3}; data.front();

[1, 2, 3]

[1] What must I change in the test to go to the next iteration? [2] What information is produced? [3] What must I do to enter the loop? [4] Can my loop reach its bounds? [5] Has my loop reached its goal? [6] How is the data processed? [7] Can my loop be entered at all? [8] What makes this loop quit?

[1] advance the loop [2] goal precondition [3] bounds precondition [4] necessary bounds [5] loop postcondition [6] loop operations and actions [7] loop guards [8] loop bounds

[1] May not repeat its actions at all [2] Keeps processing input until a particular value is found in input. [3] Repeats its actions at least once [4] Keeps processing until the output gets no closer to the answer. [5] Test for the occurrence of a particular event [6] Repeats its actions a fixed number of times [7] Conditions under which a loop will repeat its actions [8] Keeps processing until the input device signals that it is finished.

[1] guarded loop [2] sentinel loop [3] unguarded loop [4] limit loop [5] indefinite loop [6] definite loop [7] loop bounds [8] data loop

[1] Actions that occur after the loop is complete [2] Actions occuring inside the loop's body [3] Actions that occur before the loop is encountered [4] A test that determines if the loop should be entered

[1] postcondition [2] operation [3] precondition [4] bounds

What is stored in data after this runs? vector<int> data{1, 2, 3}; data.erase(v.begin());

[2, 3]

What is stored in data after this runs? vector<int> data{1, 2, 3}; data.clear();

[]

[1541] What is printed? template <typename T> ostream& mystery(ostream& out, const T* p, size_t n) { out << '['; if (n) { out << p[0]; for (size_t i = 1; i < n; i++) out << ", " << p[i]; } out << "]"; return out; } . . . int a[] = {1,2,3,4,5,1}; mystery(cout, a, 0)) << endl; [0] Does not compile. Arrays cannot be 0 length. [] [1] No output

[]

string s{"ahoy"}; auto a = s.size(); auto b = s.back(); auto c = s.at(0); auto d = s.substr(a); auto e = s.substr(0, 1);

[a] : string::size_type [b] : 'y' [c] : 'a' [d] : "" [e] : "a"

To enter a Unicode character into a C++ string, use an escape sequence starting with:

As an application programmer, which of the following names for local variables are both legal and recommended for stylistic reasons.

_ (single underscore) CamelCase

[1409] What is printed? int a[] = {1, 2, 3}; int b[] = {1, 2, 3}; if (a == b) cout << "a == b" << endl; else cout << "a != b" << endl; a != b Undefined behavior a == b Syntax error; does not compile.

a != b

Match the letter of the variable in the figure with the correct value or expression below string s{"walk the plank"}; auto a = s.find('a'); auto b = s.find('a', 3); auto c = s.find("nk"); auto d = s.find("Walk");

a : 1 b : 11 c : 12 d : string::npos

To produce one of two values (of any type) in an expression, use:

a conditional operator

To combine several test conditions to produce a single Boolean value, use:

a logical operator

Below is the illustration from the loop building strategy in Chapter 5. The highlighted lines represents: Given: the variable str is a string (may be empty) Create the counter variable, initialized to -1 🔆 If the variable str has any characters then 🔆 { Set counter to 0 Create the variable current-character as a character Place the first character in str into current-character While more-characters and current-character not a period { Add one to (or increment) the counter variable Store the next character from str in current-character } If current-character is a period then Add one to the counter to account for the period. Else Set counter to -2 } If counter is -1 the string was empty Else if counter is -2 there was no period

a loop guard

You can find the length of a string str using str.size(). In C++, size() is called:

a member function

The highlighted selection below illustrates: Given: the variable str is a string (may be empty) Create the counter variable, initialized to -1 If the variable str has any characters then { Set counter to 0 Create the variable current-character as a character Place the first character in str into current-character 🔆 While more-characters 🔆 and current-character not a period { Add one to (or increment) the counter variable Store the next character from str in current-character } If current-character is a period then Add one to the counter to account for the period. Else Set counter to -2 } If counter is -1 the string was empty Else if counter is -2 there was no period

a necessary condition

[2611] Using C++ terminology, the member Card::score() is: class Hand { std::vector<Card> cards; public: Hand() = default; virtual ~Hand() = default; void add(const Card&); virtual int score() const = 0; virtual void sort(); bool operator<(const Card& rhs) const; }; class PokerHand : public Hand { . . . } class BlackjackHand : public Hand { . . . } a virtual function an abstract method a pure virtual function an overridden member an overloaded member

a pure virtual function

The relative order of two variables is tested using:

a relational operator

[1431] Which array definition is illegal? int SIZE = 3; int a1[SIZE]; int a2[3]; int a3[3]{}; int a4[] = {1, 2, 3}; int a5[3] = {1, 2}; a2 a3 None of these a1 a5

[1432] Which array definition contains undefined values? int SIZE = 3; int a1[SIZE]; int a2[3]; int a3[3]{}; int a4[] = {1, 2, 3}; int a5[3] = {1, 2}; a3 a1 None of these a5 a2

[1433] Which array definition is initialized to all zeros? int SIZE = 3; int a1[SIZE]; int a2[3]; int a3[3]{}; int a4[] = {1, 2, 3}; int a5[3] = {1, 2}; a5 a2 None of these a3 a1

[1435] Which array definition is illegal? const int SIZE = 3; int a1[SIZE]; int a2[3]; int a3[3]{}; int a4[] = {1, 2, 3}; int a5[2] = {1, 2, 3}; a2 a5 a3 None of these a1

[1436] Which array definition produces {1, 2, 0}? int SIZE = 3; int a1[SIZE]; int a2[3]; int a3[3]{}; int a4[] = {1, 2, 3}; int a5[3] = {1, 2}; a3 a5 a2 a1 None of these

[1620] Assume you have a partially filled array a, with variables size and MAX (capacity). To append value to the array, which of these assignments is correct? a[size] = value; a[size + 1] = value; a[size - 1] = value; a[MAX - 1] = value;

a[size] = value;

[2007] What type of member function is toString()? class Alligator { public: Alligator(double w); void eat(); string toString() const; private: double weight; }; constructor None of these mutator accessor destructor

accessor

[2014] What is g()? class X { public: X(int); void f() const; int g() const; void h(int); }; None of these mutator accessor destructor constructor

accessor

[2033] In C++ terminology, frequency() is called a: class Radio { public: Radio(); explicit Radio(double); Radio(double, int); double frequency() const; double frequency(double); }; constructor method accessor data member mutator

accessor

[2608] Which member functions in the Performer class must be overridden? class Performer { public: void dance() const; virtual void sing() const; virtual void act() const = 0; }; act() sing() dance() All can be overridden None can be overridden

act()

In a client file, the value returned from calling your function is the____________?

actual value

[2614] Examine the class hierarchy below. Assume that both derived classes are concrete and completely defined. Which of the following member functions cannot be overridden in the derived classes? class Hand { std::vector<Card> cards; public: Hand() = default; virtual ~Hand() = default; void add(const Card&); virtual int score() const = 0; virtual void sort(); bool operator<(const Card& rhs) const; }; class PokerHand : public Hand { . . . } class BlackjackHand : public Hand { . . . } add() sort() score() ~Hand()

add()

[2532] Which member function(s) may 🌺 be overridden in Hobbit? class Creature { public: Creature(const string& name); virtual string name() const final; virtual string skills() const; virtual void addSkill(const string& skill); void print() const; }; class Hobbit : public Creature { . . . }; None of them addSkill(), skills() addSkill(), skills(), print() addSkill(), skills(), name()

addSkill(), skills()

Assume s1 and s2 are C++ string objects. Which of these calls is illegal? template <typename T> void addem(T a, T b) { cout << a << " + " << b << "->" << (a + b) << endl; }

addem(1.5, 2);

Which call below produces 5? template <typename T> void addem(T a, T b) { cout << a << " + " << b << "->" << (a + b) << endl; }

addem<int>(3, 2.5);

Below is the illustration from the loop building strategy in Chapter 5. The highlighted lines represents: Given: the variable str is a string (may be empty) Create the counter variable, initialized to -1 If the variable str has any characters then { Set counter to 0 Create the variable current-character as a character Place the first character in str into current-character While more-characters and current-character not a period { Add one to (or increment) the counter variable 🔆 Store the next character from str in current-character 🔆 } If current-character is a period then Add one to the counter to account for the period. Else Set counter to -2 } If counter is -1 the string was empty Else if counter is -2 there was no period

advancing the loop

age salary

[1339] Which of these is not one of the three characteristics of every variable?

alias

This code illustrates the _______ idiom. if (n % 2 == 1) cout << "Odd" << endl; else cout << "Even" << endl;

alternative action

[2030] On the second line of this code, the object named myRadio is: Radio myRadio(98.6, 8); cout << myRadio.frequency() << endl; an implicit parameter an instance variable a function modifier an explicit parameter the function return value

an implicit parameter

The highlighted selection below illustrates: Given: the variable str is a string (may be empty) Create the counter variable, initialized to -1 If the variable str has any characters then { Set counter to 0 Create the variable current-character as a character Place the first character in str into current-character While more-characters and 🔆 current-character not a period 🔆 { Add one to (or increment) the counter variable Store the next character from str in current-character } If current-character is a period then Add one to the counter to account for the period. Else Set counter to -2 } If counter is -1 the string was empty Else if counter is -2 there was no period

an intentional condition

[2411] The ostream class is the/a ___________ class of fstream derived base descendent ancestor sibling

ancestor

[1830] The program a.out is run like this: ./a.out alex brent chris rodger 32 33 44 78 argc is 9 and argv[0] is "./a.out" argc is 8 and argv[0] is "alex" argc is 9 and argv[0] is "alex" argc is 9 and argv[0] is "./a" argc is 8 and argv[0] is "./a.out"

argc is 9 and argv[0] is "./a.out"

The __________________ of an operator determines the number of items it operates on?

arity

The __________________ of an operator determines the order of operations when operators share an operand?

associativity

In the classic for loop, loop control variables going from 0 to less-than n are said to employ:

asymmetic bounds

In C++, what keyword is used for type inference?

auto

Which of these selects a character (char) from a string?

auto a = s[0];

[2205] The BigNum class allows you to create arbitrarily large numbers, without loss of precision. Examine the code shown. Which expression invokes the operator defined here? BigNum a{"12345.795"}, b{".95873421"}; const BigNum operator-(const BigNum& n) {...} ≔ None of these auto c = a - b; a -= b; auto c = --b; auto c = -b; ≕

auto c = -b;

[2204] The BigNum class allows you to create arbitrarily large numbers, without loss of precision. Examine the code shown. Which expression invokes the operator defined here? BigNum a{"12345.795"}, b{".95873421"}; const BigNum BigNum::operator-(const BigNum& n) const {...} ≔ a -= b; auto c = a - b; auto c = --b; None of these auto c = -b; ≕

auto c = a - b;

[2207] The BigNum class allows you to create arbitrarily large numbers, without loss of precision. Examine the code shown. Which expression invokes the operator defined here? BigNum a{"12345.795"}, b{".95873421"}; const BigNum operator-(const BigNum&, const BigNum&) {...} ≔ None of these a -= b; auto c = a - b; auto c = --b; auto c = -b; ≕

auto c = a - b;

[1930] Given this declaration, which line below is illegal? auto p1 = unique_ptr<int>(new int{42}); (*p1)++; p1.release(); None of these are illegal auto p2 = p1; cout << *p1 << endl;

auto p2 = p1;

If a is false, which expressions need not be evaluated? if (a && b || c && d || e) . . .

If a and c are both false, which expressions need not be evaluated? if (a && b || c && d || e) . . .

b, d

[2409] The ostream class is the/a ___________ class of ofstream descendent ancestor sibling base derived

base

[2404] Expressed in C++ terminology, the relationship between the Food class and the CherryPie class is one of _____________ (Food) and ________________ (CherryPie) specialized class, generalized class derived class, base class base class, derived class concrete class, abstract class

base class, derived class

What is the output of the following? string s = "abcde"; int i = 1; while (i < 5) { cout << s.substr (i, 1); i++; }

bcde

Stream arguments to a function should:

be as general as possible (istream and ostream)

A function where an argument is converted to match a parameter When more than one match is found for the proffered arguments. A function where each argument is the same type as the corresponding parameter. A group of functions with the same name. A group of functions that have the same name and the correct number of parameters. When no match is found for the proffered arguments

best match ambiguity exact matches candidate set viable set empty set

The following is legal. Which changes the length data member inside the variable big? struct Rectangle { int length, width; } big, little;

big.length = 10;

The + arithmetic operator is a(n) __________ operator

binary

[1605] Below is a declaration for a partially-filled array. What is the correct prototype for a function add() that appends a new element to the end of the array and returns true if successful? const size_t MAX = 100; double nums[MAX]; size_t size = 0; bool add(double a[], size_t MAX, double e); bool add(double a[], size_t& size, double e); bool add(double a[], size_t size, size_t MAX, double e); bool add(double a[], size_t& size, size_t MAX, double e);

bool add(double a[], size_t& size, size_t MAX, double e);

[1607] Below is a declaration for a partially-filled array. What is the correct prototype for a function delete() that deletes the element at position pos in the array, shifts the remaining elements left, and returns true if successful? const size_t MAX = 100; double nums[MAX]; size_t size = 0; bool delete(double a[], size_t size, size_t pos); bool delete(double a[], size_t& size, size_t pos); bool delete(double a[], size_t MAX, size_t& pos); bool delete(const double a[], size_t& size, size_t pos);

bool delete(double a[], size_t& size, size_t pos);

[1606] Below is a declaration for a partially-filled array. What is the correct prototype for a function insert() that inserts a new element at position pos in the array, shifts the remaining elements right, and returns true if successful? const size_t MAX = 100; double nums[MAX]; size_t size = 0; bool insert(double a[], size_t& size, double e, size_t pos); bool insert(double a[], size_t MAX, double e, size_t pos); bool insert(double a[], size_t size, size_t MAX, double e, size_t pos); bool insert(double a[], size_t& size, size_t MAX, double e, size_t pos);

bool insert(double a[], size_t& size, size_t MAX, double e, size_t pos);

Look at the problem statement below. The _________ of the loop is that a period was encountered. [How many characters are in a sentence? Count the characters in a string until a period is encountered. If the string contains any characters, then it will contain a period. Count the period as well.]

bounds

Below is the illustration from the loop building strategy in Chapter 5. The highlighted lines represents: Given: the variable str is a string (may be empty) Create the counter variable, initialized to -1 If the variable str has any characters then { Set counter to 0 🔆 Create the variable current-character as a character Place the first character in str into current-character 🔆 While more-characters and current-character not a period { Add one to (or increment) the counter variable Store the next character from str in current-character } If current-character is a period then Add one to the counter to account for the period. Else Set counter to -2 } If counter is -1 the string was empty Else if counter is -2 there was no period

bounds precondition

String parameters should be passed to functions:

by constant reference ( const string& s) when not modified in the function. by reference (string& s) when modified in the function

Stream arguments to a function should always be passed:

by reference

The structure and variable definitions are fine. Which statements are legal? struct R { int a, b; } a, b; struct Q { int a, b; } c, d;

c = d;

If a and b are true, which expressions need not be evaluated? if (a && b || c && d || e) . . .

c, d, e

[2432] Based on the following code snippet, which of the following function calls are legal? Assume that car is a Car object and aero is an AeroCar object. class Car { public: Car(); virtual void setSpeed(double); double getSpeed() const; void display() const; }; class AeroCar : public Car { public: AeroCar(); void setSpeed(double); void setHeight(double); double getHeight() const; }; Neither A nor B car.getSpeed() and aero.getSpeed() car.getHeight() and aero.getHeight() Both A and B

car.getSpeed() and aero.getSpeed()

The try block is followed by one or more ____ blocks.

catch

What is correct for # 2? int main() { //1 { string s = "hello"; cout << s.at(5) << endl; } // 2 // 3 ( e) { cout << e. () << endl; // 4 } }

catch

Which of the following blocks is designed to catch any type of exception?

catch(...){ }

What command makes hw the current folder?

cd ~/workspace/cs150/hw

Assume c is a char variable. What type is the variable a? string s{"guten tag"}; auto len = s.size(); auto a = s.front(); s.at(len) = a; s[len] = c;

char

Which of these prototypes is the best one to use in this circumstance? int main() { string str{"To be or not to be."}; cout << "Most common letter is " << mostCommon(str) << endl; }

char mostCommon(const string&);

[1325] What is true about this code? int * choice;

choice contains an undefined address

Assume the user types "brown cow" when this code runs. What is stored in ch2? char ch1; auto ch2 = cin.get(ch1);

cin

The standard input object; analogous to a Scanner in Java Modifies and manipulates data to produce information The header used to include the standard streams A single entity that bundles data and instructions Displays the results of calculations cout stands for ___________________ The standard output object; analogous to System.out in Java The output or insertion operator endl is a _____________________ Retrieves data and stores it in variables C++ uses an ____________ library for input and output. Text enclosed in double quotes The header used for formatting real numbers Asking an object to perform certain operations

cin processing iostream object output character output cout << stream manipulator input object-oriented string iomanip sending a message

Reads one word or token from standard input

cin >> s1; (choice G)

Complete the following code in the echo filter program. char ch; while (______________) cout.put(ch);

cin.get(ch)

Assume you have a char variable named ch. How do you read one character from input?

cin.get(ch);

Assume you have a char variable named ch. How do you look ahead before reading a character? 2 Q U E S T I O N S

cin.get(ch); cin.unget(ch); cin.putback(ch); cin.seek(ch); cin.peek(ch); -- > None of these

Assume you have a char variable named ch. How do you look ahead before reading a character?

cin.peek();

Assume you have a char variable named ch. How do you "unread" a character already read?

cin.putback(ch);

[2401] ___________________ is one of the primary mechanisms that we use to understand the natural world around us. Starting as infants we begin to recognize the difference between categories like food, toys, pets, and people. As we mature, we learn to divide these general categories or classes into subcategories like siblings and parents, vegetables and dessert classification specialization generalization encapsulation

classification

Classes that contain objects as elements are called?

collections

Which of these are not process filters?

compress input by turning off echo when reading blank spaces print one sentence per line counting word transitions

In the classic for loop, which portion of code is analogous to an if statement?

condition expression

What term describes this block of code? #if __APPLE__ istringstream in(" .75"); int n = 3; in >> n; #endif

conditional compilation

In a library, the interface file:

consists of declarations or prototypes

In a library, the client or test program:

consists of function calls

In a library, the implementation file:

consists of function definitions

In a library, the makefile:

consists of instructions that produce the executable

[2202] The BigNum class allows you to create arbitrarily large numbers, without loss of precision. Which of the following operators (which are all valid) cannot be used, assuming that the BigNum constructor is non-explicit? BigNum a{9.2573e27}; auto c = 100.0 / a; ≔ const BigNum BigNum::operator/(const BigNum& rhs) const; const BigNum operator/(const BigNum& lhs, const BigNum& rhs); const BigNum operator/(double lhs, const BigNum& rhs); All of these can be used ≕

const BigNum BigNum::operator/(const BigNum& rhs) const;

[2201] The BigNum class allows you to create arbitrarily large numbers, without any approximations. Assume you have the following code. What is the best header for the required operator? BigNum a{"12345.795"}, b{".95873421"}; auto c = a * b; const BigNum operator*(const BigNum& lhs, const BigNum& rhs); BigNum BigNum::operator*(const BigNum& rhs) const; BigNum& operator*(const BigNum& lhs, const BigNum& rhs); BigNum operator*(const BigNum& lhs, const BigNum& rhs);

const BigNum operator*(const BigNum& lhs, const BigNum& rhs);

[2208] The Date class represents a day on a calendar. Examine the code shown. Which operator is called? Date d{2018, 7, 4}; auto e = d++; const Date Date::operator++(int); const Date Date::operator++(); Date& Date::operator++(); Date& Date::operator++(int);

const Date Date::operator++(int);

[2209] The Date class represents a day on a calendar. Examine the code shown. Which operator is called? Date d{2018, 7, 4}; auto e = d++; Date& operator++(Date&, int); None of these const Date operator++(Date&, int); const Date operator++(Date&); Date& operator++(Date&);

const Date operator++(Date&, int);

[1719] Which of these is a legal assignment? string name = "Houdini"; string str = c_str(name); char* cstr = name.c_str(); string* strp = name.c_str(); const char *cstr = c_str(name); const char *cstr = name.c_str();

const char *cstr = name.c_str();

To allow f() to accept the argument passed here, the parameter str should be declared as: void f( . . . str); int main() { f("hello"); }

const string&

[2016] What is X()? class X { public: X(int); void f() const; int g() const; void h(int); }; accessor destructor mutator constructor None of these

constructor

Which of the following loop patterns are used here? auto len = str.size(); while (len) out << str.at(--len);

counter-controlled loop

Which of the following loop patterns are used here? string s{"Hello CS 150"}; while (s.size()) { if (s.at(0) == 'C') break; s = s.substr(1); } cout << s << endl;

counter-controlled loop loop-and-a-half sentinel loop

As an application programmer, which of the following names for local variables are legal (even if they are unwise from a stylistic perspective).

cout 2cool CamelCase u2 integer

[1326] How can we print the address where n is located in memory? int n{500};

cout << &n << endl;

[1302] Assume that ppi correctly points to pi. Which line prints the value stored inside pi? int main() { double pi = 3.14159; double *ppi; // code goes here // code goes here }

cout << π cout << ppi; cout << &ppi; cout << *pi; → None of these

[1304] Assume that ppi correctly points to pi. Which line prints the address of ppi? int main() { double pi = 3.14159; double *ppi; // code goes here // code goes here }

cout << &ppi;

[1401] Which of these lines correctly prints 3? struct S { int a = 3; double b = 2.5; }; S obj, *p = &obj; cout << p.a << endl; cout << *p.a << endl; cout << *(p).a << endl; cout << *(p.a) << endl; cout << (*p).a << endl;

cout << (*p).a << endl;

[1303] Assume that ppi correctly points to pi. Which line prints the value stored inside pi? int main() { double pi = 3.14159; double *ppi; // code goes here // code goes here }

cout << *ppi;

[1809] Which statement displays the value 24 from the 2D array initialized here? int a[2][3] = { { 13, 23, 33 }, { 14, 24, 34 } }; cout << a[2][2]; cout << a[1][2]; cout << a[1][1]; cout << a[2][1]; None of these

cout << a[1][1];

[1811] Which statement displays the element appearing in the second row and the third column? cout << a[3][2]; cout << a[2][1]; None of these cout << a[2][3]; cout << a[1][2];

cout << a[1][2];

[1403] Which of these lines displays the eighth element of a? int a[15]; cout << a[8] << endl; cout << a(7) << endl; cout << a.at(7) << endl; cout << a[7] << endl;

cout << a[7] << endl;

Examine the following code (which is legal). Which statement is illegal? struct Money { int dollars{0}, cents{0}; } m1, m2;

cout << m1 << endl;

[1402] Which of these lines correctly prints 2.5? struct S { int a = 3; double b = 2.5; }; S obj, *p = &obj; cout << *(p).b << endl; cout << *p.b << endl; cout << p->b << endl; cout << *(p.b) << endl; cout << *p->b << endl;

cout << p->b << endl;

Given the following structure and variable definitions which statements are legal? struct Money { int dollars{0}; int cents{1}; }; Money payment;

cout << payment.dollars; payment.cents = 5;

[1305] Assume that ppi correctly points to pi. Which line prints the size (in bytes) of pi? int main() { double pi = 3.14159; double *ppi; // code goes here // code goes here }

cout << sizeof(*ppi);

[1407] Which line has undefined output? double speed[5] = {. . .}; cout << speed[5] << endl; cout << speed[0] << endl; None of these cout << speed[1] << endl; cout << speed[4] << endl;

cout << speed[5] << endl;

Which line of code can be added to print the value 4? int main() { struct S {int a, b; }; vector<S> v; S s{3, 4}; v.push_back(s); // Add code here }

cout << v.at(0).b << endl;

Complete the following code in the echo filter program. char ch; while (cin.get(ch)) _______________;

cout.put(ch)

Assume you have a char variable named ch. How do you write one character to output?

cout.put(ch);

Which of these are true? int main() { vector<int> v{1, 2, 3}; for (auto i = v.size(); i > 0; i--) cout << v.at(i) << " "; cout << endl; }

crashes when runs

In C++, the statement string s{"world"};

creates a string variable explicitly initialized with the character array "world"

In C++, the statement string s = "world";

creates a string variable implicitly initialized with the character array "world"

In C++, the statement string s{3, 'X'};

creates a string variable of size 3, filled with 'X'

The following definition: vector<double> v{3, 5};

creates a vector of [3.0, 5.0]

The following definition: vector<double> v(3, 5);

creates a vector of [5.0, 5.0, 5.0]

The following definition: vector<double> data;

creates a vector of size 0

[2606] Which member functions in the Performer class may not be overridden? class Performer { public: void dance() const; virtual void sing() const; virtual void act() const = 0; }; sing() dance() None can be overridden All can be overridden act()

dance()

Loop bounds used when reading files or processing network data.

data bounds

Examine the following definition. empID is a _____________. struct Employee { long empID; std::string lastName; double salary; };

data member

[2031] The attributes of this class are model and price. In C++ terminology, these are called: class Mobile { std::string model; double price; public: . . . }; data members instance variables class variables data attributes fields

data members

[2017] Which element is private? class Val { int data_; public: Val(int); int get() const; void print() const; }; void Val::get() { return data_; } Val::Val(int n) { data_ = n; } void Val::print() const { cout << data_; } None of these Val() print() data_ get()

data_

[1420] What is the equivalent array notation? int dates[10]; cout << (*dates) + 2 << endl; &dates[2] dates[0] + 2 dates[0] + 4 dates[2] dates[2] + 2

dates[0] + 2

[1421] What is the equivalent array notation? int dates[10]; cout << *dates + 2 << endl; &dates[2] dates[2] + 2 dates[0] + 4 dates[2] dates[0] + 2

dates[0] + 2

[1417] What is the equivalent array notation? int dates[10]; cout << (*dates + 2) + 2 << endl; dates[0] + 4 dates[2] + 2 dates[2] dates[0] + 2 &dates[2]

dates[0] + 4

[1419] What is the equivalent array notation? int dates[10]; cout << *(dates + 2) << endl; dates[2] + 2 dates[0] + 4 dates[2] &dates[2] dates[0] + 2

dates[2]

[1422] What is the equivalent array notation? int dates[10]; cout << *(dates + 2) + 2 << endl; &dates[2] dates[0] + 4 dates[0] + 2 dates[2] dates[2] + 2

dates[2] + 2

Associates a name with a type Read a value and store it in a varaible Copy a new value into an existing variable Allocates space for a variable Provides a starting value when a variable is created A named storage area that holds a value

declare input assign define initialize variable

The variable ASSIGNMENT from your homework has been ______________________.

declared

You can call a single function in several different ways by giving the function _______________:

default arguments

Which are the two major categories of loops?

definite indefinite

[1929] Given this declaration, which line below is illegal? auto p1 = make_shared<int>(42); cout << *p1 << endl; (*p1)++; delete p1; None of these are illegal auto p2 = p1;

delete p1;

[1917] Examine this code. What goes on the blank line? void f() { int *p = new int{3}; . . . ___________________ } delete p[3]; delete[] p; None of these is correct delete p; delete *p;

delete p;

[1914] Examine this code. What goes on the blank line? void f() { int *p = new int[3]{1, 2, 3}; . . . ___________________ } delete *p; delete[] p; delete p[3]; None of these is correct delete p;

delete[] p;

[1916] Examine this code. What goes on the blank line? void f() { int *p = new int[3]{1, 2, 3}; . . . ___________________ } delete[] p; delete *p; None of these is correct delete p[0]; delete[p1]; delete [p2]; delete p[];

delete[] p;

[2408] The ostream class is the/a ___________ class of ios derived ancestor sibling descendent base

derived

What Java and other OO languages call a subclass, C++ calls a ____________.

derived class

[2412] The fstream class is the/a ___________ class of istream ancestor derived sibling base descendent

descendent

Which of these are not ways that functions may be overloaded?

different function name different return type different parameter names

Executable Object file Library file Interface file Project file Client file Implementation file

digit-tester digits.o libdigits.a digits.h makefile digit tester.cpp digits.cpp

Which of these are dependencies? EXE=digit-tester OBJS=client.o digits.o $(EXE): $(OBJS) $(CXX) $(CXXFLAGS) $(OBJS) -o $(EXE)

digits.o client.o

Which of these are unguarded loops?

do-while

[1716] What prints here? const char *a = "dog", *b = a; if (strcmp(a, b)) cout << "dog == dog" << endl; else cout << "dog != dog" << endl; dog != dog dog == dog Crashes when run Does not compile

dog != dog

[1717] What prints here? const char *a = "dog", *b = a; if (a == b) cout << "dog == dog" << endl; else cout << "dog != dog" << endl; dog != dog dog == dog Crashes when run Does not compile

dog == dog

[2343] In 1735 Leonard Euler proved a remarkable result, which was the solution to the Basel Problem, first posed in 1644 by Pietro Mengoli. This result gave a simple expression The formula states that equal to the limit, as n goes to infinity, of the series Which function below is a correct recursive implementation that approximates this infinite series?

double computePI(int number) { if (number <= 1) { return 1.0;} return 1.0 / (number * number) + computePI(number - 1); }

[1604] Below is a declaration for a partially-filled array. What is the correct prototype for a function back() that returns a reference to the last element? const size_t MAX = 100; double nums[MAX]; size_t size = 0; double& back(double a[], size_t size); double& back(double a[], size_t& size); double& back(const double a[], size_t& size); double& back(double a[], size_t size, size_t MAX);

double& back(double a[], size_t size);

[2001] Which item is a mutator? class Alligator { public: Alligator(double w); void eat(); string toString() const; private: double weight; }; None of these toString() weight eat() Alligator()

eat()

Arguments passed to a function that has a constant reference parameter must be:

either lvalues or rvalues are fine

[2402] _______________—the specification of attributes and behavior as a single entity—allows us to build on our understanding of the natural world as we create software encapsulation generalization inheritance polymorphism

encapsulation

Header guards:

end with the directive #endif includes the directive #define go in every interface file start with the directive #ifndef

A(n) ____ is an occurrence of an undesirable situation that can be detected during program execution

exception

The class ____ is the base of the classes designed to handle exceptions

exception

What is correct for # 3? int main() { //1 { string s = "hello"; cout << s.at(5) << endl; } // 2 // 3 ( e) { cout << e. () << endl; // 4 } }

exception&

In a client file you should compare your function's value to the ____________?

expected value

Given the overloaded functions prototypes and the variable definition below, which of the function calls will fail to compile? int f(int&); int f(int); int f(int, int); int a = 7;

f(a);

Which prototypes in the following header file contain errors? #ifndef EXAMPLE_H #define EXAMPLE_H #include <string> string f1(int a); int f2(double); void f3(std::string& s, int n); double f4(); #endif

Which prototypes in the following header file contain errors? #ifndef EXAMPLE_H #define EXAMPLE_H string f1(int a); int f2(double); void f3(std::string& s, int n); double f4(); #endif

f1 f3

[2413] Which of these is an example of the principle of substitutability? void f1(fstream& out) { . . .} void f2(int n) { . . . } void f3(const string& s) { . . . } void f4(ios& i) { . . . } f4(cout); f1(cout); None of these f2(3.5); f3("hello");

f4(cout);

Programs that process streams of characters are called text ______________.

filters

In Line 2, what is the request? string s{"happy"}; auto pos = s.find('y');

find

What prints? string s("hello"); try { if (s.size() > 2) throw s.size(); 🔆 if (islower(s.back())) throw s.back(); 🔆 if (s == "hello") throw string("hello"); s.at(s.size()) = 'x'; cout << "one\n"; } catch (const int& e) { cout << "two\n"; } catch (const string& e) { cout << "three\n"; } catch (exception& e) { cout << "four\n"; } catch (...) { cout << "five\n"; } ➢ I F (s.size() > 2) && throw s.size() && throw s.back()

five

What prints? string s("hello"); try { if (s.size() > 20) throw 42; 🔆 if (islower(s.back())) throw "goodbye"; 🔆 if (s == "hello") throw string("hello"); s.at(s.size()) = 'x'; cout << "one\n"; } catch (const int& e) { cout << "two\n"; } catch (const string& e) { cout << "three\n"; } catch (exception& e) { cout << "four\n"; } catch (...) { cout << "five\n"; } ➢ I F (s.size() > 20) && throw 42; && (islower(s.back())) throw "goodbye";

five

Which manipulator is used to ensure that large numbers appear using regular decimal notation?

fixed

Which manipulator(s) is/are used to make sure the value 2.0/3 prints like this: 0.677?

fixed setprecision()

Which of these are guarded loops?

for while

Which of these is a flow-of-control statement?

for (auto e : s) ... if (x < 3) ... else ... while (x < 3) ...

[1619] Which loop is used when deleting an element from an array? for (j = MAX; j > size; j--) a[j - 1] = a[j]; for (j = pos; j < size; j++) a[j] = a[j + 1]; for (j = size; j > pos; j--) a[j] = a[j - 1]; for (j = size; j < MAX; j++) a[j - 1] = a[j];

for (j = pos; j < size; j++) a[j] = a[j + 1];

[1618] Which loop is used when inserting an element into an array? for (j = pos; j < size; j++) a[j] = a[j + 1]; for (j = size; j > pos; j--) a[j] = a[j - 1]; for (j = MAX; j > size; j--) a[j - 1] = a[j]; for (j = size; j < MAX; j++) a[j - 1] = a[j];

for (j = size; j > pos; j--) a[j] = a[j - 1];

What prints? string s("hello"); try { if (s.size() > 20) throw 42; if (isupper(s.back())) throw "goodbye"; if (s == "Hello") throw string("hello"); s.at(s.size()) = 'x'; cout << "one\n"; } catch (const int& e) { cout << "two\n"; } catch (const string& e) { cout << "three\n"; } catch (exception& e) { cout << "four\n"; } catch (...) { cout << "five\n"; } ➢ I F (s.size() > 2) && throw 42; && (isupper(s.back())) throw "goodbye";

four

Which of these may go into a header file?

function prototypes constant definitions

[2405] A classification hierarchy represents an organization based on _____________ and _____________. encapsulation and polymorphism abstraction and generalization abstraction and encapsulation generalization and specialization specialization and encapsulation

generalization and specialization

The input stream member function for reading a character at a time is named:

get()

[2616] Examine the class hierarchy below. Assume that both derived classes are concrete and completely defined. Which of the following member functions cannot be overridden in the derived classes? class Hand { std::vector<Card> cards; public: Hand() = default; virtual ~Hand() = default; void add(const Card&); virtual int score() const = 0; virtual void sort(); bool operator<(const Card& rhs) const; }; class PokerHand : public Hand { . . . } class BlackjackHand : public Hand { . . . } get() sort() score() ~Hand()

get()

Has a single char& parameter Returns the last character read to the input stream Examines, but does not read the next character in an input stream Replaces the last character read with any character Called implicitly when an input statement is used as a test condition. A predicate function Converts its value argument to a character and sends it to output.

get() unget() peek() putback() fail() isalpha() put()

[2024] What is the semantic error in this class definition? class Time { long seconds; public: Time(); long get(); void set(long); }; There is no semantic error. seconds should be in the private section get() is missing an argument set() is missing const at the end get() is missing const at the end

get() is missing const at the end

[2418] Which of these data members or member functions are inherited (and accessible) by the Student class? name, getName(), setName(), getID() getName(), setName(), name studentID, name, getName(), setName(), getID() getName(), setName() None of them

getName(), setName()

Reads one line of text from standard input

getline(cin, s2); (choice H)

Which of the following variables have the value 0? int global; int main { string localStr; double localDouble; }

global

Look at the problem statement below. The _________ of the loop is to count the number of characters in a sentence. [How many characters are in a sentence? Count the characters in a string until a period is encountered. If the string contains any characters, then it will contain a period. Count the period as well.]

goal

Below is the illustration from the loop building strategy in Chapter 5. The highlighted lines represents: Given: the variable str is a string (may be empty) Create the counter variable, initialized to -1 If the variable str has any characters then { Set counter to 0 Create the variable current-character as a character Place the first character in str into current-character While more-characters and current-character not a period { 🔆 Add one to (or increment) the counter variable 🔆 Store the next character from str in current-character } If current-character is a period then Add one to the counter to account for the period. Else Set counter to -2 } If counter is -1 the string was empty Else if counter is -2 there was no period

goal operation

Below is the illustration from the loop building strategy in Chapter 5. The highlighted lines represents: Given: the variable str is a string (may be empty) Create the counter variable, initialized to -1 If the variable str has any characters then { 🔆 Set counter to 0 🔆 Create the variable current-character as a character Place the first character in str into current-character While more-characters and current-character not a period { Add one to (or increment) the counter variable Store the next character from str in current-character } If current-character is a period then Add one to the counter to account for the period. Else Set counter to -2 } If counter is -1 the string was empty Else if counter is -2 there was no period

goal precondition

This code illustrates the _______ idiom. if (n % 2 == 1) cout << "Odd" << endl;

guarded action

[1922] This code: void f() { int *p = new int[3]{rand(), rand(), rand()}; if (p[1] != 0 && p[2] != 0) delete[] p; cout << p[0] / p[1] / p[2] << endl; } has a dangling pointer has a syntax error has a double delete None of these has a memory leak

has a dangling pointer

[1923] This code: int * f() { int a[] = {1, 2, 3}; return &a[1]; } None of these has a dangling pointer has a syntax error has a memory leak has a double delete

has a dangling pointer

[1924] This code: void f() { int *p = new int[3]{rand(), rand(), rand()}; if (p[1] != 0 && p[2] != 0) delete[] p; else cout << p[0] / p[1] / p[2] << endl; delete[] p; } has a double delete None of these has a dangling pointer has a syntax error has a memory leak

has a double delete

[1919] This code: void f( ) { int *p = new int[3]{rand(), rand(), rand()}; if (p[1] == 0 || p[2] == 0) throw "Divide by 0"; cout << p[0] / p[1] / p[2] << endl; delete[] p; } has a syntax error None of these has a double delete has a memory leak has a dangling pointer

has a memory leak

[1920] This code: void f() { int *p = new int[3]{rand(), rand(), rand()}; if (p[1] == 0 || p[2] == 0) return; cout << p[0] / p[1] / p[2] << endl; delete[] p; } has a memory leak has a syntax error has a double delete None of these has a dangling pointer

has a memory leak

[2028] A user-defined type created as a struct encapsulates its data to prevent accidental modification can be easily modified without affecting code that uses it. has its implementation as its interface is an interface paired with an implementation enforces type invariants

has its implementation as its interface

[2609] The member function Mime::dance() is: class Performer { public: void dance() const; }; class Mime : public Performer { public: void dance() const; }; final overloaded overridden hidden or shadowed Illegal (does not compile)

hidden or shadowed

One-way, independent decisions use:

[1603] Below is a partially-filled array. If you have a sentinel loop where the sentinel is a negative number, which of these conditions correctly reads the number named value? const size_t MAX = 100; double nums[MAX]; size_t size = 0; double value; cin >> value; if (value < 0) break; if (! (cin >> value) || value < 0) break; cin >> value; if (cin.fail() && value < 0) break; if (value >= 0 && cin >> value) . . . // process value

if (! (cin >> value) || value < 0) break;

The structure and variable definitions are fine. Which statements are legal? struct Rectangle { int length, width; } big, small;

if (big.length == small.width) . . .

After opening the input stream in, which of these cannot be used to see if the file was successfully opened?

if (in.opened()) {/* opened ok */}

[2337] Which statement ensures that r() terminates for all values of n? int mr(int n) { // code goes here return r(n - 1) + n * n; } if (n == 1) { return 1; } if (n == 0) { return 0; } if (n == 0) { return 0; } if (n < 1) { return 1; } if (n == 1) { return 1; }

if (n < 1) { return 1; }

[2340] Two quantities a and b are said to be in the golden ratio if mc040-1.jpg is equal to mc040-2.jpg. Assuming a and b are line segments, the golden section is a line segment divided according to the golden ratio: The total length (a + b) is to the longer segment a as a is to the shorter segment b. One way to calculate the golden ratio is through the continued square root (also called an infinite surd): golden ratio = mc040-3.jpg. In a recursive implementation of this function, what should be the base case for the recursion? if (number <= 1) { return pow(number, 2.0);} if (number <= 1) { return sqrt(number);} if (number <= 1) { return 0.0;} if (number <= 1) { return 1.0;}

if (number <= 1) { return 1.0;}

[2344] In 1735 Leonard Euler proved a remarkable result, which was the solution to the Basel Problem, first posed in 1644 by Pietro Mengoli. This result gave a simple expression for mc044-1.jpg. The formula states that mc044-2.jpgis equal to the limit, as n goes to infinity, of the series mc044-3.jpg. Which statement below is the correct base case for a recursive implementation that approximates this infinite series? if (number == 0) { return 1.0 / (number * number);} if (number <= 1) { return 1.0;} if (number <= 1) { return 0.0;} if (number == 1) { return (number * number);}

if (number <= 1) { return 1.0;}

Either/or decisions should use:

if . . . else

Multiple possible outputs, testing a single condition, use:

if . . . else . . . if . . . else

Leveled decisions, such as processing income taxes are best handled with:

if . . . if . . . else . . . else

Which control structure is best equipped to handle an on or off condition?

if-else statements

Which line opens the file in.txt for reading?

ifstream in("in.txt");

Which line opens the file input.txt for reading?

ifstream in("input.txt");

Create an input file stream object named in and open the text file "tuba.txt", using a single statement.

ifstream in("tuba.txt");

Create an input file stream object named in.

ifstream in;

This loop: char c; while (c = in.get()) { cout << c << endl; }

illustrates line-based stream processing

This loop: string str; while (getline(in, str)) { cout << str << endl; }

illustrates line-based stream processing

This loop: char c; while (in.get(c)) { cout << c << endl; }

illustrates raw character I/O

This loop: string str; while (in >> str) { cout << str << endl; }

illustrates token-based stream processing

The file grades.txt contains lines of text that look like this: Smith 94 Jones 75 . . . Each line of text contains the student's name (a single word) and an integer score. What is the legal way of reading one student's information, given the following code? string name; int score; ifstream in("grades.txt");

in >> name >> score;

[1306] The value for the variable a is stored: int a = 1; void f(int b) { int c = 3; static int d = 4; }

in the static storage area

[1309] The value for the variable d is stored: int a = 1; void f(int b) { int c = 3; static int d = 4; }

in the static storage area

[1322] In C++, global variables are stored:

in the static storage area

Establish an association between the input stream object named in, and the text file on disk named "pets.txt".

in.open("pets.txt");

Which control structure is best equipped to handle processing for a group of check boxes?

independent if statements

In the classic for loop, which portion is used to create the loop control variable?

initialization statement

The variable STUDENT from your homework has been ______________________.

initialized defined declared

Which of the following loop patterns are used here? int upper = 0; char ch; while (in.get(ch)) { if (ch >= 'A' && ch <= 'Z') upper++; }

inline test data loop

[1318] All of these are legal C++ statements; which of them uses the C++ reference declarator? int a = 3, b = 4;

int &x = a;

[1317] All of these are legal C++ statements; which of them uses the C++ address operator? int a = 3, b = 4;

int *p = &a;

[1319] All of these are legal C++ statements; which of them uses the C++ pointer declarator? int a = 3, b = 4;

int *p = &b;

[1427] Which pointer initialization is illegal? int a[] = {1, 3, 5, 7, 9}; int *p3 = &a[1]; None of these int *p1 = a; int *p4 = &a; int *p2 = a + 3;

int *p4 = &a;

[1315] Which of these is the preferred way to initialize a pointer so that it points to "nothing"?

int *pi = nullptr;

Legacy or assignment initialization

int a = 0;

Direct initialization

int b(3);

[1408] Which line creates an array with 5 elements? int[5] d; int b[5]; int a[4]; None of these int[] c[5];

int b[5];

[1801] Which of these is a 2D array? int d[][] int *b[2]; int a[][2]; int c[2][2];

int c[2][2];

Uniform or list initialization

int c{5};

narrowing conversion

int e(3.5);

[1827] What is the correct version of main() if you wish to process command-line arguments? int main(int argc, char* argv[]) int main(int argc[], char * argv) int main(char *argc, int argv[]) int main(char argv[], int argc) int main(string args[])

int main(int argc, char* argv[])

[1514] What is the correct prototype for mystery? (It is not supposed to modify the array.) const int a[] = {2, 4, 6, 8}; cout << mystery(a, 4) << endl; void mystery(const int a[], size_t n); int mystery(int a[], size_t n); int mystery(const int a*, size_t n); int mystery(const int *a, size_t n); int mystery(const int[] a, size_t n);

int mystery(const int *a, size_t n);

[1515] What is the correct prototype for mystery? (It may modify the array.) const int a[] = {2, 4, 6, 8}; cout << mystery(a, 4) << endl; int mystery(int[] a, size_t n); int mystery(int a, size_t n); int mystery(int *a, size_t n); int mystery(int a*, size_t n); void mystery(const int a[], size_t n);

int mystery(int *a, size_t n);

[1808] Which one of the following statements is the correct definition for a two-dimensional array of 20 rows and 2 columns of the type integer? int num[2, 20] int num[2][2]; int num[20][2]; None of these int num[20, 2];

int num[20][2];

[1320] All of these are legal C++ statements; which of them uses the C++ dereferencing operator? int a = 3, b = 4;

int x = *p;

[1321] All of these are legal C++ statements; which of them uses indirection? int a = 3, b = 4;

int x = *p;

This compiles, runs and prints 12. What is the correct parameter declaration for x?

int& x

The class ____ is designed to deal with illegal arguments used in a function call.

invalid_argument

In the C++ stream hierarchy, base class of the istream class is:

ios

In the C++ stream hierarchy, the base class of the ostream class is:

ios

In the C++ stream hierarchy, the base class of the fstream class is:

iostream

In the C++ stream hierarchy, the base class of the stringstream class is:

iostream

[1913] The variable p points to: void f() { int *p = new int[3] = {1, 2, 3}; } the first element of an array of 3 ints with the values 1,2,3 the first element of an array of 3 uninitialized ints a single int with the value 1 is undefined. Code does not compile

is undefined. Code does not compile.

In the C++ stream hierarchy, the base class of the ifstream class is:

istream

Assume the user types "brown cow" when this code runs. What type is ch2? char ch1; auto ch2 = cin.get(ch1);

istream&

[2011] What is true about user-defined types implemented using classes with private data members? it is possible to create immutable objects All of these modifications to the character of the data members requires clients to rewrite code clients can directly modify the data members of a variable you cannot enforce the invariant properties of your types

it is possible to create immutable objects

[2347] One remarkably simple formula for calculating the value of mc047-1.jpg is the so-called Madhava-Leibniz series: mc047-2.jpg = mc047-3.jpg . Consider the recursive function below to calculate this formula: double computePI(int number) { if (number <= 1) { return 1.0;} int oddnum = 2 * number - 1; return computesign(number) * 1.0 / oddnum + computePI(number - 1); } In this recursive function, what is the role of the helper function computesign? it is the recursive call in the function it checks the sign of the number and returns true if it is positive and false if negative it is called just one time to set the sign of the final result it makes sure the sign (positive or negative) alternates as each term of the series is computed

it makes sure the sign (positive or negative) alternates as each term of the series is computed

Which of the following loop patterns are used here? string s{"hello CS 150"}; for (auto e : s) { if (toupper(e)) out.put('x'); }

iterator or range loop

Which of the following loop patterns are used here? string s{"hello CS 150"}; for (auto e : s) { if (toupper(e)) break; }

iterator or range loop loop-and-a-half

Given the following structure and variable definitions, which data members are initialized? struct Employee { long empID; std::string lastName; double salary; int age; }; Employee bob;

lastName

[1411] Which assigns a value to the first position in letters? char letters[26]; letters[0] = 'a'; letters[0] = "a"; letters[1] = 'b'; letters.front() = 'a'; letters = 'a';

letters[0] = 'a';

[2215] The Point class represents x,y coordinates in a Cartesian plane. Which line of code appears in the blank? class Point { int x_{0}, y_{0}; public: int x() const; int y() const; }; bool operator==(const Point& lhs, const Point& rhs) { return ______________________________________; } this->x() == rhs.() && this->y() == rhs.y() None of these lhs.x() == rhs.() && lhs.y() == rhs.y() lhs.x_ == rhs.x_ && lhs.y_ == rhs.y_ this->x_ == rhs.x && this->y_ == rhs.y_

lhs.x() == rhs.() && lhs.y() == rhs.y()

Loop bounds often used in scientific and mathematical applications.

limit bounds

Which of the following loop patterns are used here? int n; in >> n; while (abs(n)) { out << n % 4 << endl; n /= 4; }

limit loop

Loops that do some processing and then compare the results against a boundary condition are called ________________?

limit loops

Symbols which directly represent a value Determines the direction of operations for operators at the same level Describes how many operands an operator requires Operators that require a single data value Symbol which indicates a value Determines how tightly operators bind to operands Any combination of operators and operands which yields a value A symbol that can be used to produce a value at runtime Symbol which indicates an operation A storage location containing a value Operators that require two data values

literal associativity arity unary operand precedence expression function call operator variable binary

Which of the following variables have an undefined value? int global; int main { string localStr; double localDouble; }

localDouble

To deal with logical errors in a program, such as string subscript out of range or an invalid argument to a function call, several classes are derived from the class ____.

logic_error

Which operator is used to see if all of a set of conditions is true?

logical and

Which operator is used to see if any of a set of conditions is true?

logical or

Below is the illustration from the loop building strategy in Chapter 5. The highlighted lines represents: Given: the variable str is a string (may be empty) Create the counter variable, initialized to -1 If the variable str has any characters then { Set counter to 0 Create the variable current-character as a character Place the first character in str into current-character 🔆 While more-characters and current-character not a period 🔆 { Add one to (or increment) the counter variable Store the next character from str in current-character } If current-character is a period then Add one to the counter to account for the period. Else Set counter to -2 } If counter is -1 the string was empty Else if counter is -2 there was no period

loop bounds

Using the loop-building strategy from Chapter 5, which of these are part of the loop mechanics?

loop bounds bounds precondition advancing the loop

Below is the illustration from the loop building strategy in Chapter 5. The highlighted lines represents: Given: the variable str is a string (may be empty) Create the counter variable, initialized to -1 If the variable str has any characters then { Set counter to 0 Create the variable current-character as a character Place the first character in str into current-character While more-characters and current-character not a period { Add one to (or increment) the counter variable Store the next character from str in current-character } 🔆 If current-character is a period then 🔆 Add one to the counter to account for the period. Else Set counter to -2] } If counter is -1 the string was empty Else if counter is -2 there was no period

loop postcondition

x in the expression x = 3;

lvalue

Arguments passed to a function that has a non-constant reference parameter must be:

lvalues

int i = 1; int n; do { cin >> n; i++; } while (n % 2); cout << i << endl;

lvalues

Examine the following code (which is legal). Which statement is legal? struct Money { int dollars{0}, cents{0}; } m1, m2;

m1 = m2;

What command only builds hw04?

make

What command hands in hw04 for course credit?

make submit

What command checks hw04 for correctness?

make test

[2034] In C++ terminology, the two members named frequency() are: class Radio { public: Radio(); explicit Radio(double); Radio(double, int); double frequency() const; double frequency(double); }; non-member functions methods constructors data members member functions

member functions

Examine the following definition. What is the syntax error? struct Employee { long empID; std::string lastName; double salary; }

missing a semicolon after the structure definition

[2010] What is true about user-defined types implemented using classes with private data members? clients can directly modify the data members of a variable you cannot enforce the invariant properties of your types it is not possible to create immutable objects All of these modifications to the character of the data members does not require clients to rewrite code

modifications to the character of the data members does not require clients to rewrite code

[2406] When you create your own new, user-defined types, there are three different strategies you can use. Which of these is not one of those strategies? defining a class from scratch extending an existing class by adding new features combining simpler classes to create a new classes modifying an existing class

modifying an existing class

This code illustrates the _______ idiom. auto n = 3; if (n % 2 == 1) n = -n; else if (n < 0) n++; else if (n % 2 = 0) n--; else n = 0;

multiple selection

[2006] What type of member function is eat()? class Alligator { public: Alligator(double w); void eat(); string toString() const; private: double weight; }; mutator None of these destructor accessor constructor

mutator

[2015] What is h()? class X { public: X(int); void f() const; int g() const; void h(int); }; mutator destructor constructor accessor None of these

mutator

[2032] In C++ terminology, frequency(double) is called a: class Radio { public: Radio(); explicit Radio(double); Radio(double, int); double frequency() const; double frequency(double); }; constructor mutator data member accessor method

mutator

What happens when this code fragment runs? istringstream in("12"); int n; in >> n;

n is set to 12

What happens when this code fragment runs? istringstream in("12.5"); int n; in >> n;

n is set to 12

[2419] Which of these data members or member functions are inherited but not directly accessible by the Student class? getID() studentID name setName() getName()

name

Assume that name is a string object. Which of these expressions are legal?

name += 'X' name < "bob" name == "sally" name += "fred"

[2539] Which member function(s) should not be overridden in Hobbit? class Creature { public: Creature(const string& name); virtual string name() const final; virtual string skills() const; virtual void addSkill(const string& skill); void print() const; }; class Hobbit : public Creature { . . . }; None of them name(), print() skills(), name(), print() addSkill(), skills(), name()

name(), print()

[2540] Which member function(s) in Hobbit cause a compiler error? class Creature { public: Creature(const string& name); virtual string name() const final; virtual string skills() const; virtual void addSkill(const string& skill); void print() const; }; class Hobbit : public Creature { public: string name() const override; string skills() const override; void addSkill(const string&) override; void print() override; }; None of them name(), print() skills(), name(), print() addSkill(), skills(), name()

name(), print()

Code is written in machine (and assembly) language for a specific processor; thus it is non-portable or machine dependent.

native code machine language

Which control structure is best equipped to handle processing for income taxes?

nested if statements

A named constant, which can only be initialized once, is known as a ______________________.

non-modifiable lvalue

const double PI = 3.14159;

non-modifiable value

[1602] Below is a partially-filled array. When adding elements to this array in a loop, what statement(s) correctly updates the array with value? const size_t MAX = 100; double nums[MAX]; size_t size = 0; double value; nums[size] = value; nums[size++] = value; nums[++size] = value; size++; nums[size] = value;

nums[size++] = value;

Create an output file stream object named out and open the text file "expenses.dat", using a single statement.

ofstream out("expenses.dat");

Create an output file stream object named out.

ofstream out;

Which line opens the file out.txt for writing?

ofstream out; out.open("out.txt");

What prints? string str = "Hello"; for (int i = str.size() - 1; i >= 0; i--) cout << str.at(i);

olleH

[1902] The variable *p is located: void f() { int *p = new int; } on the heap None of these in the static storage area on the stack

on the heap

[1307] The value for the variable b is stored: int a = 1; void f(int b) { int c = 3; static int d = 4; }

on the stack

[1308] The value for the variable c is stored: int a = 1; void f(int b) { int c = 3; static int d = 4; }

on the stack

[1901] The variable p is located: void f() { int *p = new int; } in the static storage area None of these on the heap on the stack

on the stack

A catch block can have, at most, ____ catch block parameter(s).

one

What prints? string s("hello"); try { if (s.size() > 20) throw 42; if (isupper(s.back())) throw "goodbye"; if (s == "Hello") throw string("hello"); s.at[s.size()] = 'x'; 🔆 cout << "one\n"; } catch (const int& e) { cout << "two\n"; } catch (const string& e) { cout << "three\n"; } catch (exception& e) { cout << "four\n"; } catch (...) { cout << "five\n"; }

one

[2615] Examine the class hierarchy below. Assume that both derived classes are concrete and completely defined. Which of the following member functions cannot be overridden in the derived classes? class Hand { std::vector<Card> cards; public: Hand() = default; virtual ~Hand() = default; void add(const Card&); virtual int score() const = 0; virtual void sort(); bool operator<(const Card& rhs) const; }; class PokerHand : public Hand { . . . } class BlackjackHand : public Hand { . . . } sort() score() ~Hand() operator<()

operator<()

After writing data to an ostringstream object named os, you can retrieve the string it contains by using:

os.str()

In the C++ stream hierarchy, the base class of the ofstream class is:

ostream

Examine the following code (which is legal). What is the correct prototype for an aggregate output operator? struct Money { int dollars{0}, cents{0}; } m1, m2;

ostream& operator<<(ostream& out, const Money& m);

Examine the following code (which is legal). What is the correct prototype for an aggregate output operator? struct Time { int hours{0}, minutes{0}, seconds{0}; };

ostream& operator<<(ostream& out, const Time& m);

[2214] The Time class represents the time of day on a clock. Examine the code shown. Which operator is called? Time t(8, 30, "a"); cout << t << endl; ≔ ostream& ostream::operator<<(const Time&); ostream operator<<(ostream, Time); ostream& operator<<(ostream&, const Time&); None of these ostream&Time::operator<<(ostream&, const Time&); ≕

ostream& operator<<(ostream&, const Time&);

[2414] Which of these is an example of the principle of substitutability? void f1(ostream& out) { . . .} void f2(double n) { . . . } void f3(const char * s) { . . . } void f4(ofstream& i) { . . . } f2(3); ostringstream out; f1(out); None of these f4(cout); f3("hello");

ostringstream out; f1(out);

Use the output stream object named out to create the text file on disk named "totals.txt".

out.open("totals.txt");

Which fragment completes this code segment? string fmt(double n, int decimals) { ostringstream out; out << fixed << setprecision(decimals); out << n; return _______________; }

out.str()

Different functions that have the same name, but take different arguments, are said to be:

overloaded

[2605] Specialization inheritance means that the derived class may add new data members and member functions, and may also _________________ the virtual member functions in the base class. hide override overload cast delete

override

[1348] Assume that p is a pointer to the first of 50 contiguous integers stored in memory. What is the address of the first integer appearing after this sequence of integers?

p + 50;

[1414] What is the address of the first pixel in the last row of this image? Pixel *p; // address of pixel data int w, h; // width and height of image p + w + h p + w + (h - 1) p + w * h p + w * (h - 1) None of these are correct

p + w * (h - 1)

[1351] Here is a fragment of pseudocode for the negative() function in H12. What statement represents the underlined portion of code? Let p point to beginning of the image Let end be pixel one past the end of the image While p != end Invert the red component Move p to next component

p++;

[1349] Assume that p1 is a pointer to an integer and p2 is a pointer to a second integer. Both integers appear inside a large contiguous sequence in memory, with p2 storing a larger address. How many total integers are there in the slice between p1 and p2?

p2 - p1;

[1311] The variable buf is a pointer to a region of memory storing contiguous int values. (This is similar to your homework, where you had a region of memory storing unsigned char values.) The four lines shown here are legal. Which operation is illegal? int *p1 = buf; const int *p2 = buf; int * const p3 = buf; const int * p4 const = buf;

p3++;

[1416] Which returns the last pixel on the first row of this image? Pixel *p; // address of pixel data int w, h; // width and height of image p[w - 1] *p[w - 1] None of these are correct p[w] - 1 p + w - 1

p[w - 1]

What prints here? auto a = 3, b = 3; cout << (a == b ? "panda": "tiger") << endl;

panda

Given the following structure and variable definitions which statements are illegal? struct Money { int dollars{0}; int cents{1}; }; Money payment;

payment{1} = 5; cout << Money.dollars; Money{1} = Money{0};

[2515] Below is a class hierarchy. Which assignment results in slicing? class Pet { . . . }; class Puppy : public Pet { . . . }; class Kitty : public Pet { . . . }; class Ducky : public Pet { . . . }; Pet pet; Puppy pup; Kitty kit; Duck duck; pet = kit; kit = duck; pup = pet; duck = pet;

pet = kit;

[2514] Below is a class hierarchy. Which assignment results in slicing? class Pet { . . . }; class Puppy : public Pet { . . . }; class Kitty : public Pet { . . . }; class Ducky : public Pet { . . . }; Pet pet; Puppy pup; Kitty kit; Duck duck; pet = pup; pup = pet; Pet* p = &pet; Pet& p = duck;

pet = pup;

Look at the problem statement below. The _________ of the loop is read a character and increment a counter. [How many characters are in a sentence? Count the characters in a string until a period is encountered. If the string contains any characters, then it will contain a period. Count the period as well.]

plan

[1338] What is the term used to describe a variable with stores a memory address?

pointer

In Line 2, what is the result of this function call? string s{"happy"}; auto pos = s.find('y');

pos

[1301] Which line below points ppi to pi? int main() { double pi = 3.14159; double *ppi; // code goes here // code goes here }

ppi = π

The __________________ of an operator determines which operands the operator binds with?

precedence

Which of the following loop patterns are used here? size_t pos = 0; char ch; in.get(ch); while (ch != 'Q') { pos++; in.get(ch); }

primed loop sentinel loop

What happens when this code fragment compiles and runs? #define N #ifndef N cout << "Hello"; #else cout << "Goodbye"; #endif

prints "Goodbye"

What happens when this code fragment compiles and runs? #define N #ifdef N cout << "Hello"; #else cout << "Goodbye"; #endif

prints "Hello"

What does this code do? int x = 0; vector<int> v{1, 3, 2}; for (auto e : v) e += x; cout << x << endl;

prints 0

[2012] The __________ of a class specifies how clients interact with a class. public interface private implementation private interface public implementation None of these

public interface

[2513] Below is a class hierarchy. Which assignment will fail to compile? class Pet { . . . }; class Puppy : public Pet { . . . }; class Kitty : public Pet { . . . }; class Ducky : public Pet { . . . }; Pet pet; Puppy pup; Kitty kit; Duck duck; pup = pet; Pet* p = &pet; Pet& p = duck; Puppy& pr = pup;

pup = pet;

The following is legal. Which is the correct way to access a data member in the Rectangle variable named r? struct Rectangle { int length, width; };

r.length

The expression cin.get(ch) does which of these?

reads the next character in input and stores it in ch returns a reference to cin that can be tested

[2403] Inheritance gives your programs the ability to express _______________ between classes dependencies composition encapsulation relationships

relationships

[2345] In 1735 Leonard Euler proved a remarkable result, which was the solution to the Basel Problem, first posed in 1644 by Pietro Mengoli. This result gave a simple expression for mc045-1.jpg. The formula states that mc045-2.jpgis equal to the limit, as n goes to infinity, of the series mc045-3.jpg. Which statement below is the recursive case for a recursive implementation that approximates this infinite series? return 1.0 / (number * number) + computePI(number - 1); return 1.0 + computePI(number); return 1.0 + computePI(number - 1); return 1.0 / (number * number) + computePI(number);

return 1.0 / (number * number) + computePI(number - 1);

[2341] Two quantities a and b are said to be in the golden ratio if mc041-1.jpg is equal to mc041-2.jpg. Assuming a and b are line segments, the golden section is a line segment divided according to the golden ratio: The total length (a + b) is to the longer segment a as a is to the shorter segment b. One way to calculate the golden ratio is through the continued square root (also called an infinite surd): golden ratio If the function double golden (int) is a recursive implementation of this function, what should be the recursive call in that function? return sqrt (1.0 + golden(number)); return sqrt (1.0 + golden(number - 1)); return (1.0 + golden(number - 1)); return (1.0 + golden(number));

return sqrt (1.0 + golden(number - 1));

[2332] What changes about this function if lines 4 and 5 are swapped? 1. void myfun(string word) 2. { 3. if (word.length() == 0) { return; } 4. myfun(word.substr(1, word.length())); 5. cout << word[0]; 6. } prints the characters of the string in both forward and reverse order creates infinite recursion nothing reverses the order in which the characters of the string are printed

reverses the order in which the characters of the string are printed

x in the expression y = x;

rvalue

In Line 2, what is the receiver? string s{"happy"}; auto pos = s.find('y');

[1720] Which line makes the comment correct? char s[50]; char *t = "ac"; // Make s into a C-string "ac" s = t; s = "ac"; s[0] = t[0]; s[1] = t[1]; s[2] = t[2]; None of these s[0] = t[0]; s[1] = t[1];

s[0] = t[0]; s[1] = t[1]; s[2] = t[2];

Given the following structure and variable definitions, which data members are uninitialized? struct Employee { long empID; std::string lastName; double salary; int age; }; Employee bob;

salary age empID

Given the following structure and variable definitions, which data members are initialized? struct Employee { long empID; std::string lastName; double salary; int age; }; Employee bob{};

salary age lastName empID

[2501] Below is a class hierarchy for card games. Which of the Hand member functions may be overridden in the GoFishHand class? class Hand { std::vector<Card> cards; public: void add(const Card&); Card get(size_t index) const; virtual int score() const; }; class PokerHand : public Hand { . . . }; class BlackjackHand : public Hand { . . . }; class GoFishHand : public Hand { . . . }; get() add() score() all of them none of them

score()

[2617] Examine the class hierarchy below. Assume that both derived classes are concrete and completely defined. Which of the following member functions must be overridden in the derived classes? class Hand { std::vector<Card> cards; public: Hand() = default; virtual ~Hand() = default; void add(const Card&); virtual int score() const = 0; virtual void sort(); bool operator<(const Card& rhs) const; }; class PokerHand : public Hand { . . . } class BlackjackHand : public Hand { . . . } add() get() score() sort()

score()

Loop bounds used when searching through input.

sentinel bounds

Which of these are indefinite loops?

sentinel bounds limit bounds data bounds

A loop that reads data until some special value is found is called a:

sentinel loop

Which control structure is best equipped to handle processing for a group of radio buttons?

sequential if statements

[2025] What is the semantic error in this class definition? class Time { long seconds; public: Time(); long get() const; void set(long) const; }; seconds should be in the private section get() is missing an argument set() should not have const at the end There is no semantic error. get() should not have const at the end

set() should not have const at the end

[2431] Which member function from the Question class is overridden in the ChoiceQuestion class? class Question { public: virtual void setText(const string&); virtual void setAnswer(const string&); virtual void display() const; }; class ChoiceQuestion : public Question { public: void setText(const string&); void setAnswer(int, const string&); void display(const string&) const; }; setText() Question() display() setAnswer()

setText()

Which manipulator is used to change the padding character used in a column like: 0045?

setfill()

Which manipulator(s) is/are used to make sure the number 45 prints like this: 0045?

setfill() setw()

[2410] The ostream class is the/a ___________ class of istream ancestor derived descendent sibling base

sibling

The ++ arithmetic operator is a(n) __________ operator

side effect unary

The pattern of parameter types and order is called the function's:

signature

[2607] Which member functions in the Performer class may be overridden (but need not be)? class Performer { public: void dance() const; virtual void sing() const; virtual void act() const = 0; }; act() sing() dance() All can be overridden None can be overridden

sing()

[1611] Below is a template function, push(), that adds elements to the end of a partially-filled array, returning true if successful. The function has an error; what is the error? template <typename T> bool push(T* a, size_t& size, size_t MAX, T e) { if (size < MAX) { a[size] = e; return true; } return false; } a should be a const T* size should be incremented size should be passed by value Condition should be size <= MAX

size should be incremented

[1613] Below is index(), a template function that works with a partially-filled array. The function searches the array a for the value e and returns its position. It returns NOT_FOUND if the value does not it exist in the array. The function contains an error; what is the error? const size_t NOT_FOUND = static_cast<size_t>(-1); template <typename T> size_t index(const T* a, size_t& size, T e) { for (size_t i = 0; i < size; i++) if (a[i] == e) return i; return NOT_FOUND; } a should not be a const T* e should be passed by reference The condition should go to i <= size size should not be passed by reference

size should not be passed by reference

All of these are declared in the <string> header; which are member functions?

size() front() find() at()

[1430] Which expression returns the number of countries? string countries[] = {"Andorra", "Albania", . . . }; len(countries) sizeof(countries) * sizeof(countries[0]) sizeof(countries) None of these sizeof(countries) / sizeof(countries[0])

sizeof(countries) / sizeof(countries[0])

[1429] Which expression returns the number of countries? string countries[] = {"Andorra", "Albania", . . . }; sizeof(countries) len(countries) sizeof(countries) / sizeof(string) None of these sizeof(countries) * sizeof(countries[0])

sizeof(countries) / sizeof(string)

[2618] Examine the class hierarchy below. Assume that both derived classes are concrete and completely defined. Which of the following member functions are the derived classes allowed (but not required to) override? class Hand { std::vector<Card> cards; public: Hand() = default; virtual ~Hand() = default; void add(const Card&); virtual int score() const = 0; virtual void sort(); bool operator<(const Card& rhs) const; }; class PokerHand : public Hand { . . . } class BlackjackHand : public Hand { . . . } get() score() add() sort()

sort()

What happens when this code fragment runs in C++ 11? cout << sqrt(-2) << endl;

sqrt() returns a not-a-number error value

Read and write characters to memory using streams Connect a disk file to an input or output stream Use the predefined stream objects cin and cout Determine the category of a character Modify the way that memory is converted to characters on input or output

sstream fstream iostream cctype iomanip

[1703] Where are the characters "CS 150" stored in memory? char s1[1024] = "Hello"; void f() { const char *s2 = "Goodbye"; char s3[] = "CS 150"; } stack heap static storage area (read-only) static-storage area (read/write)

stack

[1704] Where is the pointer s2 stored in memory? char s1[1024] = "Hello"; void f() { const char *s2 = "Goodbye"; char s3[] = "CS 150"; } stack heap static storage area (read-only) static-storage area (read/write)

stack

[2338] Infinite recursion can lead to an error known as stack overflow heap exhaustion heap fragmentation memory exception

stack overflow

[1702] Where are the characters "Goodbye" stored in memory? char s1[1024] = "Hello"; void f() { const char *s2 = "Goodbye"; char s3[] = "CS 150"; } stack heap static storage area (read-only) static-storage area (read/write)

static storage area (read-only)

[1701] Where are the characters "Hello" stored in memory? char s1[1024] = "Hello"; void f() { const char *s2 = "Goodbye"; char s3[] = "CS 150"; } stack heap static storage area (read-only) static-storage area (read/write)

static-storage area (read/write)

The logic_error and runtime_error classes are defined in the header file ____.

stdexcept

What happens when this code fragment runs? cout << stoi("12") << endl;

stoi() returns 12

[1904] The variable p: void f( ) { int *p = new int; } stores the value 0 stores a memory address None of these is uninitialized

stores a memory address

What prints here? auto a = 3, b = 3; cout << (a != b ? "panda": a % 2 ? "stork": "tiger") << endl;

stork

[1725] Which library function performs an equivalent operation on C-strings? string s1 = "Hello"; string s2 = "World"; s1 = s1 + s2; strlen() strcpy() strcmp() strcat() None of these

strcat()

[1727] Which library function performs an equivalent operation on C-strings? string s1 = f(), s2 = f(); if (s1 < s2) . . . strlen() strcpy() strcmp() strcat() None of these

strcmp()

[1726] Which library function performs an equivalent operation on C-strings? string s1 = "Hello"; string s2 = "World"; s1 = s2; strlen() strcpy() strcmp() strcat() None of these

strcpy()

The C++11 standard library provides the function stoi() to convert a string to an integer. Which library is it found in?

string

Examine this code. Which is the best prototype? int age; string name = read("Enter your name, age: ", age);

string read(const string&, int&)

Produces the empty string

string s1; (choice A)

Implicitly converts a character array to a string object

string s2 = "hello"; (choice B)

Explicitly converts a character array to a string object

string s3{"world"}; (choice C)

Produces a string from multiple copies of a single character

string s4(20, '-'); (choice D)

Produces a string that may contain quotes or backslashes

string s5(R"("bob")"); (choice E)

Examine this code. Which is the best prototype? string s = "dog"; cout << upper(s) << endl; // DOG cout << s << endl; // dog

string upper(const string&)

Examine this code. Which is the best prototype? string s = "dog"; upper(s); cout << s << endl; // DOG

string upper(const string&)

To allow f() to change the argument passed here, the parameter str should be declared as: void f( . . . str); int main() { string s = "hello"; f(s); }

string&

What value is stored in a after this runs? string s{"ABCDEFD"}; auto a = s.find('G');

string::npos

What type is the variable len? string s{"guten tag"}; auto len = s.size(); auto a = s.front(); s.at(len) = a; s[len] = c;

string::size_type

[1728] Which library function performs an equivalent operation on C-strings? string s = mystery(); if (s.size() > 3) . . . strlen() strcpy() strcmp() strcat() None of these

strlen()

Examine the following definition. Employee is the _____________. struct Employee { long empID; std::string lastName; double salary; };

structure tag

An incomplete, yet compilable, linkable and executable function is called a ___________ ?

stub

[1501] Below is a cumulative algorithm using an array and a range-based loop. What is printed? (Assume this is inside main() with all includes, etc.) int a[] = {2, 4, 6, 8}; int sum = 0; for (auto e : a) sum += e; cout << "sum->" << sum << endl; Compiles but crashes with an endless loop. Does not compile. Cannot use range-loop on arrays. sum->20 sum->0 Compiles and runs, but results are undefined.

sum->20

[1504] Below is a cumulative algorithm using an array and a range-based loop. What is printed? (Assume this is inside main() with all includes, etc.) int a[] = {2, 4, 6, 8}; int sum = 0; for (auto e : a) sum =+ e; cout << "sum->" << sum << endl; Does not compile. Cannot use range-loop on arrays. sum->8 Compiles and runs, but results are undefined. sum->20 Does not compile; e is undefined.

sum->8

[1347] Examine this version of the swap() function, which is different than the two versions appearing in your text. How do you call it? void swap(int * x, int & y) { . . . } . . . int a = 3, b = 7; // What goes here ?

swap(&a, b);

[1346] Examine this version of the swap() function, which is different than the two versions appearing in your text. How do you call it? void swap(int& x, int * y) { . . . } . . . int a = 3, b = 7; // What goes here ?

swap(a, &b);

Decisions based on numbered blocks of code are best handled with:

switch

[2221] The Point class represents x,y coordinates in a Cartesian plane. Which line of code appears completes this operator? (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } const Point operator++(int n) { Point temp(*this); . . . return ________________; } }; temp *this Does not compile; changes arity of operator; should be unary, not binary. Does not compile; must be a non-member function. Does not compile; cannot change data members of object; no mutators.

temp

In C++ the parameterized collection classes are called __________?

templates

In Line 2, what is the implicit argument? string s{"happy"}; auto pos = s.find('y');

the address of s

[2339] Infinite recursion can occur because the base case is missing one of the necessary termination conditions the recursive function is called more than once the recursive case is invoked with simpler arguments a second function is called from the recursive one

the base case is missing one of the necessary termination conditions

Which control structure is best equipped to set a variable to one or two possible values?

the conditional operator

Which of these is not a technique for implementing a sentinel loop?

the counter-controlled pattern

[1912] The variable p points to: void f() { int *p = new int[3]{1, 2, 3}; } ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ is undefined. Code does not compile. the first element of an array of 3 uninitialized ints a single int with the value 1 the first element of an array of 3 ints with the values 1,2,3 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

the first element of an array of 3 ints with the values 1,2,3

[2029] A Fraction denominator must not ever become 0. You can enforce this invariant through: class Fraction { . . . public: Fraction(int, int); Fraction get() const; Fraction set(int, int); }; the implementation of the accessor member the selection of data members the implementation of the mutator member by using the access modifier private in place of public the implementation of a destructor

the implementation of the mutator member

When you call a function, the compiler must know:

the number of arguments to pass the name of the function the type of each argument the kind of value returned if any

Which control structure is best equipped to handle numeric selections made from a menu?

the switch statement

What prints? string s("hello"); try { auto x = s.at(s.size()); 🔆 cout << "one" << endl; } catch (const string& e) { cout << "two\n"; } catch (exception& e) { cout << "three\n"; } catch (...) { cout << "four\n"; }

three

What statement is used to signal other parts for your program that a particular error has occurred?

throw

Which of the following statements throws a valid exception in C++?

throw 2;

Complete the code fragment below, which is designed to throw an illegal_length exception if string variable accountNumber has more than seven characters. if (accountNumber.size() > 7) { __________________________________; }

throw illegal_length("Account number exceeds maximum length");

What prints here? auto a = 4, b = 3; cout << (a == b ? "panda": a % 2 ? "stork": "tiger") << endl;

tiger

What prints here? auto a = 3, b = 3; cout << (a != b ? "panda": "tiger") << endl;

tiger

[2004] Which of these is an accessor? class Alligator { public: Alligator(double w); void eat(); string toString() const; private: double weight; }; toString() weight Alligator() None of these eat()

toString()

Complete the following code in the lower filter program. char ch; while (cin.get(ch)) cout.put(____________);

tolower(ch)

Complete the following code in the upper filter program. char ch; while (cin.get(ch)) cout.put(____________);

toupper(ch)

Which of these are not state filters?

translating data from one form to another search for a particular value in a stream copy a file

What is correct for # 1? int main() { //1 { string s = "hello"; cout << s.at(5) << endl; } // 2 // 3 ( e) { cout << e. () << endl; // 4 } }

try

Code that may cause an error should be placed in a ______________ block and code that handles the error should be inside a ___________ block?

try, catch

What prints? string s("hello"); try { if (s.size() > 2) throw 42; 🔆 if (islower(s.back())) throw "goodbye"; 🔆 if (s == "hello") throw string("hello"); s.at(s.size()) = 'x'; cout << "one\n"; } catch (const int& e) { cout << "two\n"; } catch (const string& e) { cout << "three\n"; } catch (exception& e) { cout << "four\n"; } catch (...) { cout << "five\n"; } ➢ I F (s.size() > 2) && throw 42; && throw "goodbye";

two

What prints? string s("hello"); try { if (s.size() > 5) throw s.size(); 🔆 if (isupper(s.back())) throw s.back(); 🔆 if (s == "hello") throw string("hello"); s.at(s.size()) = 'x'; cout << "one\n"; } catch (const string& e) { cout << "two\n"; } catch (exception& e) { cout << "three\n"; } catch (...) { cout << "four\n"; } ➢ I F (s.size() > 5) && throw s.size() && throw s.back()

two

A C++ string that contains Unicode characters should be preceded by:

The - operator is a(n) __________ operator

unary binary

Assume that the user enters: Steve Gilbert 68 3.5 What value is stored in age? string name; int age; double gpa; cout << "Enter your name, age and gpa: "; cin >> name >> age >> gpa;

undefined

In the classic for loop, which portion of code is executed after the last statement in the loop body?

update expression

In the classic for loop, which portion of code is not followed by a semicolon?

update expression

Types such as classes, structures and enumerations Types such as pointers, arrays and references Built-in types, such as int and double The "kind" of a variable Read a value and store it in a variable Types such as string and vector

user-defined types derived types primitive types data type input library types

Which of these are unavoidable conditions? auto floor ??? // some number; bool v1 = floor >= 0 || floor <= 20; bool v2 = floor <= 0 && floor >= 20; bool v3 = floor <= 0 || floor >= 20; bool v4 = floor >= 0 && floor <= 20; bool v5 = floor >= 0 || floor < 20; bool v6 = floor >= 0 && floor > 20; bool v7 = floor >= 0 || floor > 20; bool v8 = floor >= 0 && floor < 20;

v1 v5

Which of these are impossible conditions? auto floor ??? // some number; bool v1 = floor >= 0 || floor <= 20; bool v2 = floor <= 0 && floor >= 20; bool v3 = floor <= 0 || floor >= 20; bool v4 = floor >= 0 && floor <= 20; bool v5 = floor >= 0 || floor < 20; bool v6 = floor >= 0 && floor > 20; bool v7 = floor >= 0 || floor > 20; bool v8 = floor >= 0 && floor < 20;

[] and () denote whether a range includes or excludes an endpoint: [ includes the endpoint ( excludes the endpoint [] = 'Closed', includes both endpoints () = 'Open', excludes both endpoints [) and (] are both 'half-open', and include only one endpoint Which variable correctly indicates that the variable floor is in the range (0...20)? auto floor ??? // some number; bool v1 = floor >= 0 || floor <= 20; bool v2 = floor <= 0 && floor >= 20; bool v3 = floor <= 0 || floor >= 20; bool v4 = floor >= 0 && floor <= 20; bool v5 = floor >= 0 || floor < 20; bool v6 = floor >= 0 && floor > 20; bool v7 = floor >= 0 || floor > 20; bool v8 = floor >= 0 && floor < 20;

[] and () denote whether a range includes or excludes an endpoint: [ includes the endpoint ( excludes the endpoint [] = 'Closed', includes both endpoints () = 'Open', excludes both endpoints [) and (] are both 'half-open', and include only one endpoint Which variable correctly indicates that the variable floor is in the range [0...20]? auto floor ??? // some number; bool v1 = floor >= 0 || floor <= 20; bool v2 = floor <= 0 && floor >= 20; bool v3 = floor <= 0 || floor >= 20; bool v4 = floor >= 0 && floor <= 20; bool v5 = floor >= 0 || floor < 20; bool v6 = floor >= 0 && floor > 20; bool v7 = floor >= 0 || floor > 20; bool v8 = floor >= 0 && floor < 20;

[] and () denote whether a range includes or excludes an endpoint: [ includes the endpoint ( excludes the endpoint [] = 'Closed', includes both endpoints () = 'Open', excludes both endpoints [) and (] are both 'half-open', and include only one endpoint Which variable correctly indicates that the variable floor is in the range [0...20)? auto floor ??? // some number; bool v1 = floor >= 0 || floor <= 20; bool v2 = floor <= 0 && floor >= 20; bool v3 = floor <= 0 || floor >= 20; bool v4 = floor >= 0 && floor <= 20; bool v5 = floor >= 0 || floor < 20; bool v6 = floor >= 0 && floor > 20; bool v7 = floor >= 0 || floor > 20; bool v8 = floor >= 0 && floor < 20;

Used to access the data inside a variable Determines the amount of memory required and the operations permitted on a variable The meaning assigned to a set of bits stored at a memory location An object whose value is an address in memory Expression using the address operator Expression using the reference declarator Expression using the dereferencing operator Expression using the pointer declarator Expression returning the number of allocated bytes used by an object Address value 0

variable name variable type variable value pointer p = &a; int x = 3; y = *a; double * v; sizeof(Star) nullptr

Elements always allocated on the heap How arrays are passed to functions What happens to an array when passed to a function const int *array int * const array const int * const array sizeof(a) / sizeof(a[0]) end(a) - begin(a) for (auto e : a) . . x = 0; for (auto e : a) x += e; x = a[0]; for (auto e: a) if (e > x) x = e; auto p = a; while (p != end(a)) p++; cout << a[0]; while (i < len) cout << ", " << a[i++];

vector ⠀⠀ by address ⠀⠀ decays ⠀⠀ Elements may not be modified; pointer may be ⠀⠀ Elements in may be modified; pointer may not ⠀⠀ Neither pointer nor elements in may be modified ⠀⠀ Elements in array using arithmetic ⠀⠀ Elements in array using pointer difference ⠀⠀ A range-based loop ⠀⠀ Cumulative algorithm ⠀⠀ Extreme values algorithm ⠀⠀ Iterator-based loop ⠀⠀ Fence-post algorithm

Which defines a vector to store the salaries of ten employees?

vector<double> salaries(10);

[1313] These pointer should point to "nothing". Which is not correctly initialized?

vector<int> *vp;

[1802] Which function prototype could process a 2D array? void f(int **a); void f(int[][] a); void v(int a[][]); void f(int a[2][]); void (f(int a[][2]);

void (f(int a[][2]);

[2507] Below is a class hierarchy for card games. Assuming that these are the only classes and that the concrete classes are correctly completed, which of the following non-member functions are polymorphic? class Hand { std::vector<Card> cards; public: void add(const Card&); Card get(size_t index) const; virtual int score() const; }; class PokerHand : public Hand { . . . }; class BlackjackHand : public Hand { . . . }; class GoFishHand : public Hand { . . . }; void draw(const Hand h) { . . . } void draw(const Hand& h) { . . . } void draw(const PokerHand* h) { . . . } void draw(const GoFishHand& h) { . . . }

void draw(const Hand& h) { . . . }

[2508] Below is a class hierarchy for card games. Assuming that these are the only classes and that the concrete classes are correctly completed, which of the following non-member functions are polymorphic? class Hand { std::vector<Card> cards; public: void add(const Card&); Card get(size_t index) const; virtual int score() const; }; class PokerHand : public Hand { . . . }; class BlackjackHand : public Hand { . . . }; class GoFishHand : public Hand { . . . }; void draw(const Hand h) { . . . } void draw(const Hand* h) { . . . } void draw(const PokerHand& h) { . . . } void draw(const GoFishHand* h) { . . . }

void draw(const Hand* h) { . . . }

The following code is logically correct. What is the semantically correct prototype for mystery()? vector<double> v; mystery(v);

void mystery(vector<int>&);

[2502] Below is a class hierarchy for card games. Which is the correct signature for a function that can print the score of any playing card hand? class Hand { std::vector<Card> cards; public: void add(const Card&); Card get(size_t index) const; virtual int score() const; }; class PokerHand : public Hand { . . . }; class BlackjackHand : public Hand { . . . }; class GoFishHand : public Hand { . . . }; void printScore(Hand h); void printScore(const Hand h); void printScore(const Hand* h); void printScore(BlackjackHand& h); void printScore(const PokerHand& h);

void printScore(const Hand* h);

Which of these prototypes is the best one to use in this circumstance? int main() { string str{"TO BE OR NOT TO BE"}; properCase(str); cout << str << endl; }

void properCase(string&);

This compiles, runs and prints 4, 3. What is the correct prototype? int x = 3, y = 4; swap(x, y); cout << x << ", " << y << endl;

void swap(int& a, int& b);

[2005] Which of these is part of the implementation? class Alligator { public: Alligator(double w); void eat(); string toString() const; private: double weight; }; toString() Alligator() eat() weight All of these

weight

The function ____ returns a string containing an appropriate message.

what

What is correct for # 4? int main() { //1 { string s = "hello"; cout << s.at(5) << endl; } // 2 // 3 ( e) { cout << e. () << endl; // 4 } }

what

Indefinite limit loop that reduces its input Indefinite limit loop that uses successive approximations Counter-controlled symmetric loop for producing a sequence of data Indefinite data loop that uses raw input Counter-controlled asymmetric loop for processing characters Iterator loop that may change its container Iterator loop that cannot change its container Counter-controlled loop for processing substrings Indefinite data loop that uses formatted input

while (n!=0) {n/=2;} while(abs(g1-g2) >= EPSILON) {...} for (int i = 12; i <= 19; i ++) {...} while(cin.get(ch)) {...} for (size_t i = 0, len = s.size(); i < len; i++) {...} for(auto&e : col) {...} for(auto e: col) {...} for(size_t i=4, slen =4; len = s.size(); i <len; i++) {...} while(cin >> n)

[1601] Below is a partially-filled array. If you are adding elements to this array in a loop, what is the correct loop bounds condition? const size_t MAX = 100; double nums[MAX]; size_t size = 0; while (MAX < size) . . . while (size < MAX) . . . while (size <= MAX) . . . for (size = 0; size < MAX; size++) . . .

while (size < MAX) . . .

[2226] The Point class represents x,y coordinates in a Cartesian plane. Which line of code appears completes this operator? The operator translates the point by its argument. (Members written inline for this problem.) class Point { int x_{0}, y_{0}; public: Point(int x, int y): x_{x}, y_{y} {} int x() const { return x_; } int y() const { return y_; } Point& operator+=(const Point& rhs) { ________________________________ return *this; } }; ≔ *this = rhs; rhs.x_ += this->x_; rhs.y_ += this->y; this->x() += rhs.x(); this->y() += rhs.y(); Does not compile; no access to private members object x_ += rhs.x(); y_ += rhs.y(); ≕

x_ += rhs.x(); y_ += rhs.y();

What is stored in s after this code runs? string s{"xyzw"}; s.at(2) = 'Y';

xyYw

Assume int x, y, z; Shorthand assignment Post increment Undefined behavior Widening conversion Pre decrement Chained assignment Narrowing conversion Mixed-type expression

y += z; x++; x = z++ - ++z; double a = y; --z; x = y = z = 10; z = 3.15; auto v = x * 2.3;

[2322] What is the value of r("xhixhix")? string r(const string& s) { if (s.size()) { auto c = s.at(0); auto t = c == 'x' ? 'y' : c; return t + r(s.substr(1)); } return 0; } Stack overflow yyyyyyy xyyxyyx yhiyhiy xyhixyhixy

yhiyhiy

[2009] What is true about user-defined types implemented using classes with private data members? clients can directly modify the data members of a variable it is not possible to create immutable objects All of these you can enforce the invariant properties of your types modifications to the character of the data members requires clients to rewrite code

you can enforce the invariant properties of your types

In C++, what is true about concatenating string literals (character arrays)?

you do it by separating the string literals with white space

[2321] What is the value of r("xxhixx")? string r(const string& s) { if (s.empty()) return ""; if (s.at(0) == 'x') return 'y' + r(s.substr(1)); return s.at(0) + r(s.substr(1)); } xxyyxx yyhiyy xyxyhixyxy yxyxhixyyx Stack overflow

yyhiyy

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