Deck 9: Pointers

Question 1

The weak_ptr can share ownership of a piece of dynamically allocated memory.

Answer 1

False

Question 2

The __________, also known as the address operator, returns the memory address of a variable.

A) asterisk (* )
B) ampersand ( & )
C) percent sign ( % )
D) exclamation point ( ! )
E) None of these

Answer 2

B

Question 3

The unique_ptr is the sole owner of a piece of dynamically allocated memory.

Answer 3

True

Question 4

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

Question 5

To use any of the smart pointers in C++11 you must use the following directive in the header file:
#include

Question 6

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

Question 7

Assuming myValues is an array of int values and index is an int variable, both of the following statements do the same thing.

Question 8

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.

Question 9

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

Question 10

In C++11, the nullptr keyword was introduced to represent the address 0.

Question 11

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

Question 12

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

Question 13

With pointer variables you can __________ manipulate data stored in other variables.

A) never
B) seldom
C) indirectly
D) All of these
E) None of these

Question 14

With pointer variables you can access but not modify data in other variables.

Question 15

A pointer can be used as a function argument, giving the function access to the original argument.

Question 16

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.

Question 17

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

Question 18

It is legal to subtract a pointer variable from another pointer variable.

Question 19

An array name is a pointer constant because the address stored in it cannot be changed at runtime.

Question 20

The ampersand (&) is used to dereference a pointer variable in C++.

Question 21

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

Question 22

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

Question 23

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

Question 24

What will the following statement output?
Cout << &num1;

A) the value stored in the variable named num1
B) the memory address of the variable named num1
C) the number 1
D) the string &num1
E) None of these

Question 25

When you pass a pointer as an argument to a function, you must

A) declare the pointer value again in the function call
B) dereference the pointer value in the function prototype
C) use the #include statement
D) not dereference the pointer in the function's body
E) None of these

Question 26

If you are using an older computer that does not support the C++11 standard, you should initialize pointers with

A) the integer 0 or the value NULL
B) the null terminator '\0'
C) a nonzero value
D) Any of these
E) None of these

Question 27

What will the following code output?
Int number = 22;
Int *var = &number;
Cout << *var << endl;

A) the address of number
B) 22
C) an asterisk followed by 22
D) an asterisk followed by the address of number

Question 28

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.

A) null pointer
B) smart pointer
C) dereferenced pointer
D) None of these

Question 29

Not all arithmetic operations can be performed on pointers. For example, you cannot __________ or __________ pointers.

A) multiply, divide
B) +=, -=
C) add, subtract
D) increment, decrement
E) None of these

Question 30

A pointer variable may be initialized with

A) any nonzero integer value
B) a valid address in the computer's memory
C) an address less than zero
D) any nonzero number
E) None of these

Question 31

Dynamic memory allocation occurs

A) when a new variable is created by the compiler
B) when a new variable is created at runtime
C) when a pointer fails to dereference the right variable
D) when a pointer is assigned an incorrect address
E) None of these

Question 32

The following statement __________ cin >> *num3;

A) stores the keyboard input in the variable num3
B) stores the keyboard input into the pointer num3
C) is illegal in C++
D) stores the keyboard input into the variable pointed to by num3
E) None of these

Question 33

The __________ and __________ operators can be used to increment or decrement a pointer variable.

A) addition, subtraction
B) ++, --
C) modulus, division
D) All of these
E) None of these

Question 34

The following statement __________ int *ptr = new int;

A) results in a compiler error
B) assigns an integer less than 32767 to the variable ptr
C) assigns an address to the variable ptr
D) creates a new pointer named int
E) None of these

Question 35

If a variable uses more than one byte of memory, for pointer purposes its address is

A) the address of the last byte of storage
B) the average of all the addresses used to store that variable
C) the address of the first byte of storage
D) the address of the second byte of storage
E) None of these

Question 36

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

Question 37

Every byte in the computer's memory is assigned a unique

A) pointer
B) address
C) dynamic allocation
D) name
E) None of these

Question 38

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

Question 39

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

Question 40

A pointer variable is designed to store

A) any legal C++ value
B) only floating-point values
C) an integer
D) a memory address
E) None of these

Question 41

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;

A) five memory addresses
B) 0
C) 3
D) 2
E) 1

Question 42

Select 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

A) multiplication
B) division
C) addition
D) subtraction
E) modulus

Question 43

Select all that apply. Of the following, which statements have the same meaning?

A) int *ptr = nullptr;
B) int ptr = nullptr;
C) *int ptr = nullptr;
D) int* ptr = nullptr;
E) int ptr* = nullptr;

Question 44

Select all that apply. Which of the following can be used as pointers?

A) array names
B) numeric constants
C) keywords
D) None of these

Question 45

Which of the following defines a unique_ptr named uniq that points to a dynamically allocated int?

A) unique_ptr int( new int );
B) unique_ptr int( new uniq );
C) unique_ptr uniq( new int );
D) unique_ptr uniq( new int );
E) None of these

Question 46

After the code shown executes, which of the following statements is true?
Int numbers[] = {0, 1, 2, 3, 4};
Int *ptr = numbers;
Ptr++;

A) ptr will hold the address of numbers[0]
B) ptr will hold the address of the second byte within the element numbers[0]
C) ptr will hold the address of numbers[1]
D) this code will not compile

Question 47

What will the following code output?
Int number = 22;
Int *var = &number;
Cout << var << endl;

A) the address of number
B) 22
C) an asterisk followed by 22
D) an asterisk followed by the address of number