CSCI 1 Chapter 9
The ________ and ________ operators can be used to increment or decrement a pointer variable. ] addition, subtraction ++, -- modulus, division All of these None of these
++, --
The following statement ________. cin >> *num3; -stores the keyboard input in the variable num3 -stores the keyboard input into the pointer num3 is illegal in C++ -stores the keyboard input into the variable pointed to by num3 - None of these
-stores the keyboard input into the pointer num3 is illegal in C++
What will the following code output? int *numbers = new int[5]; for (int i = 0; i <= 4; i ++) *(numbers + i) = i; cout << numbers[2] << endl; five memory addresses 0 3 2 1
2
What will the following code output? int number = 22; int *var = &number; cout << *var << endl; the address of number 22 an asterisk followed by 22 an asterisk followed by the address of number
22
A pointer variable may be initialized with any nonzero integer value a valid address in the computer's memory an address less than zero any nonzero number None of these
a valid address in the computer's memory
In C++11, the ________ keyword was introduced to represent address 0. a)nullptr b)NULL c)weak_ptr d)shared_ptr e)None of these
a)nullptr
A function may return a pointer but the programmer must ensure that the pointer a)still points to a valid object after the function ends b)has not been assigned an address c)was received as a parameter by the function d)has not previously been returned by another function e) None of these
a)still points to a valid object after the function ends
Assuming ptr is a pointer variable, what will the following statement output? cout << *ptr; a)the value stored in the variable whose address is contained in ptr b)the string "*ptr" c)the address of the variable whose address is stored in ptr d)the address of the variable stored in ptr e)None of these
a)the value stored in the variable whose address is contained in ptr
elect all that apply. Select as many of the following options that make this sentence TRUE: The contents of pointer variables may be changed with mathematical statements that perform multiplication division addition subtraction modulus
addition, subtraction
Every byte in the computer's memory is assigned a unique pointer address dynamic allocation name None of these
address
The ________, also known as the address operator, returns the memory address of a variable. astreric(*) ampersand (&) percent(%) exclamation point(!) none of these
ampersand(&)
Which of the following can be used as pointers? array names numeric constants keywords None of these
array name
The following statement ________. int *ptr = new int; results in a compiler error assigns an integer less than 32767 to the variable ptr assigns an address to the variable ptr creates a new pointer named int None of these
assigns an address to the variable ptr
When you work with a dereferenced pointer, you are actually working with a)a variable whose memory has been allocated b)a copy of the value pointed to by the pointer variable c) the actual value of the variable whose address is stored in the pointer variable d) None of these
c) the actual value of the variable whose address is stored in the pointer variable
Which of the following is TRUE about this statement? sum += *array++; a)This statement is illegal in C++. b)This statement will cause a compiler error. c)This statement assigns the dereferenced pointer's value, then increments the pointer's address. d)This statement increments the dereferenced pointer's value by one, then assign that value. e)None of these
c)This statement assigns the dereferenced pointer's value, then increments the pointer's address.
Use the delete operator only on pointers that were a)never used b)not correctly initialized c)created with the new operator d)dereferenced inappropriately e)None of these
c)created with the new operator
Which of the following statements deletes memory that has been dynamically allocated for an array? a)int array = delete memory; b)int delete[ ]; c)delete [] array; d)new array = delete; e)None of these
c)delete [] array;
In the following statement, what does int mean? int *ptr = nullptr; a)The variable named *ptr will store an integer value. b)The variable named *ptr will store an asterisk and an integer value c)ptr is a pointer variable and will store the address of an integer variable. d)The variable named *ptr will store the value in nullptr. e)None of these
c)ptr is a pointer variable and will store the address of an integer variable.
When the less than operator (<) is used between two pointer values, the expression is testing whether a)the value pointed to by the first is less than the value pointed to by the second b)the value pointed to by the first is greater than the value pointed to by the second c)the address of the first variable comes before the address of the second variable in the computer's memory d)the first variable was declared before the second variable e)None of these
c)the address of the first variable comes before the address of the second variable in the computer's memory
What will the following statement output? a)cout << &num1; b)the value stored in the variable named num1 c)the memory address of the variable named num1 the number 1 d)the string &num1 e)None of these
c)the memory address of the variable named num1 the number 1
What does the following statement do? double *num2; a)Declares a double variable named num2 b)Declares and initializes a pointer variable named num2 c)Initializes a pointer variable named num2 d)Declares a pointer variable named num2 e)None of these
d)Declares a pointer variable named num2
Which of the following statements displays the address of the variable numb? a)cout << numb; b)cout << *numb; c) cin >> &numb; d)cout << &numb; e)None of these
d)cout << &numb;
Which of the following statements is NOT valid C++ code? a)int ptr = &num1; b)int ptr = int *num1; c)float num1 = &ptr2; d)All of these are valid e)All of these are invalid
e)All of these are invalid
The ampersand (&) is used to dereference a pointer variable in C++ -true -false
false
The weak_ptr can share ownership of a piece of dynamically allocated memory. -true -fasle
false
With pointer variables you can access but not modify data in other variables -true -false
false
With pointer variables you can ________ manipulate data stored in other variables. never seldom indirectly All of these None of these
indirectly
Select all that apply. Of the following, which statements have the same meaning? int *ptr = nullptr; int ptr = nullptr; *int ptr = nullptr; int* ptr = nullptr; int ptr* = nullptr;
int *ptr = nullptr; int* ptr = nullptr;
A pointer variable is designed to store any legal C++ value only floating-point values an integer a memory address None of these
memory address
Not all arithmetic operations can be performed on pointers. For example, you cannot ________ or ________ pointers. multiply, divide +=, -= add, subtract increment, decrement None of these
multipy, divide
When you pass a pointer as an argument to a function, you must declare the pointer value again in the function call dereference the pointer value in the function prototype use the #include statement not dereference the pointer in the function's body None of these
none
After the code shown executes, which of the following statements is TRUE? int numbers[] = {0, 1, 2, 3, 4}; int *ptr = numbers; ptr++; ptr will hold the address of numbers[0] ptr will hold the address of the second byte within the element numbers[0] ptr will hold the address of numbers[1] this code will not compile
ptr will hold the address of numbers[1]
To help prevent memory leaks from occurring in C++11, a ________ automatically deletes a chunk of dynamically allocated memory when the memory is no longer being used. null pointer smart pointer dereferenced pointer None of these
smart pointer
What will the following code output? int number = 22; int *var = &number; cout << var << endl; the address of number 22 an asterisk followed by 22 an asterisk followed by the address of number
the address of number
If a variable uses more than one byte of memory, for pointer purposes its address is the address of the last byte of storage the average of all the addresses used to store that variable the address of the first byte of storage the address of the second byte of storage None of these
the address of the first byte of storage
If you are using an older computer that does NOT support the C++11 standard, you should initialize pointers with the integer 0 or the value NULL the null terminator '\0' a nonzero value Any of these None of these
the integer 0 or the value NULL
A pointer can be used as a function argument, giving the function access to the original argument. -true -fasle
true
An array name is a pointer constant because the address stored in it cannot be changed at runtime. -true -false
true
Assuming myValues is an array of int values and index is an int variable, both of the following statements do the same thing. 1. cout << myValue [index] << endl; 2. cout << *(myValues + index) << endl; -true -false
true
C++ does not perform array bounds checking, making it possible for you to assign a pointer the address of an element out of the boundaries of an array. -true -false
true
In C++11 you can use smart pointers to dynamically allocate memory and not worry about deleting the memory when you are finished using it. -true -false
true
In C++11, the nullptr keyword was introduced to represent the address 0. -true -false
true
It is legal to subtract a pointer variable from another pointer variable. -true -false
true
The unique_ptr is the sole owner of a piece of dynamically allocated memory. -true -false
true
To use any of the smart pointers in C++11 you must use the following directive in the header file: -true -false
true
Which of the following defines a unique_ptr named uniq that points to a dynamically allocated int? unique_ptr int( new int ); unique_ptr int( new uniq ); unique_ptr uniq( new int ); unique_ptr uniq( new int ); None of these
unique_ptr uniq( new int );
Dynamic memory allocation occurs when a new variable is created by the compiler when a new variable is created at runtime when a pointer fails to dereference the right variable when a pointer is assigned an incorrect address None of these
when a new variable is created at runtime