Midterm Intro C++

Given function Multiply(u, v) that returns u * v, and Add(u, v) that returns u + v, which expression corresponds to: Add(Multiply(x, Add(y, z)), w)

(x * (y + z)) + w

What is the output, if the input is 3 2 4 5? All variables are ints. cin >> num; for (i = 0; i < num; ++i) { cin >> curr; cout << curr; }

245

Which assigns the last vector element with 20? vector<int> userNum(N_SIZE);

userNum.at(N_SIZE - 1) = 20;

In an instruction like: z = x + y, the symbols x, y, and z are examples of _____.

variables

Which declares two related integer vectors named personName and personAge each with 50 elements? vector<int> personName(50); vector<int> personAge(50); vector<int> personName, personAge = 50; vector<int> personName = 50; vector<int> personAge = 50;

vector<int> personName(50);vector<int> personAge(50);

The numNegatives variable counts the number of negative values in the vector userVals. What should numNegatives be initialized to? vector<int> userVals(20); unsigned int i; numNegatives = XXX; for (i = 0; i < userValues.size(); ++i) { if (userValues.at(i) < 0) { numNegatives = numNegatives + 1;} }

0

Which is the correct representation of 3.9e-5?

0.000039

The binary equivalent of the decimal number 15 is _____ .

00001111

What is the output, if n is 3? for (int i = 1; i <= n; ++i) { int factorial = 1; factorial = factorial * i; cout << factorial << " "; }

1 2 3

How many elements does the vector declaration create? vector<int> scores(10); // Vector declaration scores.at(0) = 25; scores.at(1) = 22; scores.at(2) = 18; scores.at(3) = 28;

10

What is the output? int num = 10; while (num <= 15) { cout << num << " "; if (num == 12) { break; } ++num; } cout << "Done";

10 11 12 Done

What are the ending contents of the vector? Choices show elements in index order 0, 1, 2. vector<int> yearsList(3); yearsList.at(0) = 5; yearsList.at(1) = yearsList.at(0); yearsList.at(0) = 10; yearsList.at(2) = yearsList.at(1);

10, 5, 5

If the input is 12, what is the final value for numItems? int x; int numItems = 0; cin >> x; if (x <= 12) {numItems = 100; }else {numItems = 200; } numItems = numItems + 1;

101

Which is not a valid identifier? name1 first_name 1stName firstName

1stName

Given a vector/array with values 5, 10, 15, 20, 25, what are the fewest number of swaps needed to reverse the list?

2

Given myVector initially has 5 elements with values 3, 4, 6, 8, and 9. What are the values in myVector after the following? myVector.resize(2);

3,4

What is the output if count is 4? for (i = count; i > 0; --i) { // Output count }

4321

Given vector userVal has 4 elements. What is the size of userVal after the following? userVal.resize(5);

5

What is the ending value of y if x is 50? y and x are ints. y = (x < 21) ? 100 : x;

50

How many x's will be output? i = 1; while (i <= 3) { j = 1; while (j <= i) { cout << "x";++j; } cout << endl; ++i; }

6

What is the output, if the input is 3 2 1 0? cin >> x; while (x > 0) { cout << 2 * x << " "; }

666666666...infinte

What is the ending value of z? x = 0; y = 3; z = pow(x + 2, y);

8

For what values of x will "Medium" be output? If x > 40: Output "Large"Else If x > 20: Output "Medium"Else If x > 10: Output "Small"

Any x from 21 to 40

Which item converts a high-level language program to low-level machine instructions?

Compiler

For which quantity is a double the best type?

Height of a building

For an enumerated type like below, the compiler assigns what kind of value to RED, GREEN, and BLACK. enum CarColor {RED, GREEN, BLACK};

Integer

Which input for char c causes "Done" to be output next? c = 'y'; while (c = 'y') { // Do somethingcout << "Enter y to continue, n to quit: "; cin >> c; } cout << "Done";

No such value (infinite loop)

For what values of x does the default case execute in the code below? x is declared as an integer. switch (x) { case 2:...break; case 3:...break; case 4:...break; default:... // When does this execute? }

Only for values that are not 2, 3, or 4

Which is true for the following code? char userText[10]; userText[0] = 'B'; userText[1] = 'o'; userText[2] = 'o'; userText[3] = 'k'; userText[4] = '\0'; ...userText[3] = 't';

Printing the array userText will work fine because the new string is 4 characters and the array size is 10.

RAM is an abbreviation that stands for:

Random Access Memory

Which expressions for YYY and ZZZ will output "Young" for ages less than 20 and "Young Adolescent" for ages between 10 and 20? int u; cin >> u; if (YYY) { cout << "Young"; if (ZZZ) { cout << " Adolescent"; } }

YYY: u < 20 ZZZ: u > 10

A sequence of instructions that solves a problem is called a(n) _____ .

algorithm

The _____ is a process that manages programs and interfaces with peripherals.

operating system

Which character array declaration is appropriate? char name[5] = "Alexandria"; char name[5] = "Alexa"; char name[5] = "Alexander"; char name[5] = "Alex";

char name[5] = "Alex";

Which declaration assigns a variable with 5 such that the value can not be later changed? const int = 5; int NUM_ITEMS = 5; int numItems = 5; const int NUM_ITEMS = 5;

const int NUM_ITEMS = 5;

Which YYY outputs the string in reverse?Ex: If the input is "Oh my", the output is "ym hO". int i; string str; getline(cin, str); for (YYY){ cout << str.at(i); }

i = str.length() - 1; i >= 0; --i)

Which if branch executes when an account lacks funds and has not been used recently? hasFunds and recentlyUsed are booleans and have their intuitive meanings.

if (!hasFunds && !recentlyUsed)

Which XXX will output only values up to 3? i is an int. for (i = 1; i < 10; i++) { cout << i << " "; XXX { break; } }

if (i == 3)

Which is the simplest expression that is true only when myChar is among a-z or A-Z? isalpha(myChar) isalpha(tolower(myChar)) isalpha(tolower(myChar)) || isalpha(toupper(myChar)) isalpha(myChar) && !isspace(myChar)

isalpha(myChar)

Which assigns the vector's first element with 99? vector<int> myVector(4);

myVector.at(0) = 99;

For the string "Orange", what character is at index 3?

n

Which expression is most appropriate for randomly choosing a day of the week?

rand() % 7;

An identifier can _____ . contain a period contain spaces start with an underscore be a reserved word

start with an underscore

Which statement appends an exclamation point at the end of myStr? char myStr[10] = "Yay";

strcat(myStr, "!");

Which XXX and YYY will loop as long as the input is an integer less than 100? Choices are in the form XXX / YYY. cin >> w; while (XXX) { // Do something YYY; } w < 100 / (nothing) w >= 100 / (nothing) w < 100 / cin >> w w >= 100 / cin >> w

w < 100 / cin >> w

For an integer constant x, which statement will yield a compiler error? y = x; w = x + 1; z = x + x; x = y + 1;

x = y + 1;

What is the output? int columns; int rows; for (rows = 0; rows < 2; ++rows) { for (columns = 0; columns < 3; ++columns) { cout << "x";} cout << endl;}

xxx xxx