Deck 10: Pointers

Question 1

Which of the following statements is not valid C++ code?

A)float num1 = &ptr2;
B)int ptr = &num1;
C)int ptr = int *num1;
D)All of the above are valid.
E)All of the above are invalid.

Answer 1

E

Question 2

To dereference a structure pointer and simultaneously access a member of the structure, the appropriate operator to use is

A)an asterisk, *.
B)the dereference operator, <-.
C)the structure pointer operator, ->.
D)the ampersand, &.
E)None of the above

Answer 2

C

Question 3

A function may return a pointer, but the programmer must ensure that the pointer

A)is pointing to an object that is still valid after the return of the function.
B)was received as a parameter by the function.
C)has been assigned an address.
D)has not previously been returned by another function.
E)None of the above

Answer 3

A

Question 4

Which arithmetic operations can be performed on pointers?

A)Multiplication, division, addition, and subtraction
B)Addition , subtraction , preincrement, and postincrement
C)Only multiplication and addition
D)All arithmetic operations that are legal in C++
E)None of the above

Question 5

The and operators can respectively be used to increment and decrement a pointer variable.
A)All of the above

A)modulus, division
B)None of the above
B)dereferencing, indirection _C)++_, --

Question 6

A statement that displays the address of the variable num1 is

A)cout << &(*num1);.
B)cout << &num1;.
C)cout << num1;.
D)cout << *num1;.
E)None of the above

Question 7

The statement int *ptr; means

A)the variable called *ptr will store an asterisk and an integer value.
B)ptr is a pointer variable that will store the address of an integer variable.
C)the variable called ptr will store an integer value.
D)All of the above
E)None of the above

Question 8

Any time you use the new operator, it is good practice to

A)clear the data from the old operator
B)use a preprocessor directive.
C)use delete afterwards to free the memory allocated by new.
D)All of the above
E)None of the above

Question 9

If arr is an array identifier and k is an integer, the expression arr[k] is equivalent to

A)&arr[k].
B)arr + k.
C)*(arr + k).
D)*arr + k.
E)None of the above

Question 10

When the less than ( < )operator is used between two pointer variables, the expression is testing whether

A)the address of the first variable comes before the address of the second variable in the computer's memory.
B)the value pointed to by the first is less than the value pointed to by the second.
C)the first variable was declared before the second variable.
D)the value pointed to by the first is greater than the value pointed to by the second.
E)None of the above

Question 11

The statement double *num;

A)defines a pointer variable called num.
B)defines a variable of type double called num.
C)initializes a variable called *num.
D)defines and initializes a pointer variable called num.
E)None of the above

Question 12

The code segment int *ptr; has the same meaning as

A)int* ptr;.
B)int ptr*;.
C)*int ptr;.
D)int ptr;.
E)None of the above

Question 13

If s is a structure variable and p, a pointer, is a member of the structure, the statement ^{cout << *s.p;} will

A)output the value stored in s.
B)output the dereferenced value pointed to by p.
C)output the address stored in p.
D)result in a compiler error.
E)None of the above

Question 14

The statement cout << *ptr; will output

A)the address of the variable stored in ptr.
B)the string "*ptr".
C)the value stored in the variable whose address is contained in ptr.
D)the address of the variable whose address is stored in ptr.
E)None of the above

Question 15

You may use the type pointer to a structure as the type of a

A)function parameter.
B)function return type.
C)structure member.
D)All of the above
E)None of the above

Question 16

The statement cin >> *p;

A)stores the keyboard input into the variable pointed to by p.
B)is illegal in C++.
C)stores the keyboard input into the pointer called p.
D)stores the keyboard input into the variable p.
E)None of the above

Question 17

When you work with a dereferenced pointer, you are actually working with

A)a copy of the value pointed to by the pointer variable.
B)a variable whose memory has been deallocated.
C)the variable whose address is stored in the pointer variable.
D)All of the above
E)None of the above

Question 18

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

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

Question 19

Assuming that arris an array identifier, the statement sum += *arr;

A)will always result in a compiler error.
B)is illegal in C++.
C)adds the address of the pointer arr to sum.
D)adds the value stored in arr[0] to sum.
E)None of the above

Question 20

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

A)name.
B)address.
C)dynamically allocated value.
D)value.
E)None of the above

Question 21

The expression *s->p; is only meaningful if s is a pointer to a structure and p is a pointer that is a member of that structure.

Question 22

It is possible for a structure to contain as a member a pointer to its own structure type.

Question 23

A pointer with the value 0 (zero)is called the NULL pointer.

Question 24

When the is placed in front of a variable name, it returns the address of that variable.

A)asterisk ( * )
B)ampersand ( & )
C)semicolon ( ; )
D)conditional operator
E)None of the above

Question 25

Which of the following statements correctly deletes a dynamically- allocated array pointed to by p?

A)delete [ ] p;
B)delete array p;
C)delete p;
D)p delete[ ];
E)None of the above

Question 26

If dynamically allocated memory is not freed,

A)a run- time error informs your user that the program did not free memory space.
B)the source code will not link correctly.
C)the system may run out of memory.
D)it results in a compiler error.
E)None of the above

Question 27

A pointer may be initialized with

A)the value of a floating- point variable.
B)the address of an existing object of the appropriate type.
C)the value of a floating- point constant.
D)All of the above
E)None of the above

Question 28

If a variable occupies more than one byte of memory, its address is

A)general delivery.
B)the address of the last byte of storage allocated to it.
C)the average of the addresses used to store the variable.
D)the address of the first byte of storage allocated to it.
E)None of the above

Question 29

The delete operator should only be used on pointers that

A)have been correctly initialized.
B)have not yet been used.
C)are appropriately dereferenced.
D)point to storage allocated by the new operator.
E)None of the above

Question 30

If Circle is a structure type, the statement Circle *pcirc;

A)defines a structure variable called *pcirc.
B)initializes a Circle pointer.
C)defines a structure pointer called pcirc.
D)is illegal in C++.
E)None of the above

Question 31

A pointer variable is designed to store

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

Question 32

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

Question 33

A pointer variable may be initialized with

A)the address of an existing variable of the appropriate type.
B)any non- zero integer value.
C)A and B are both true.
D)None of the above

Question 34

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

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

Question 35

can be used as pointers.

A)C++ string objects
B)Punctuation marks
C)Array names
D)All of the above
E)None of the above

Question 36

The term pointer can be used interchangeably with

A)address.
B)decimal pointer.
C)variable.
D)counter pointer.
E)None of the above

Question 37

The statement int *ptr = new int; acquires memory to hold an integer and then

A)creates a new pointer called int.
B)sets ptr to point to the allocated memory.
C)initializes the allocated memory to 0.
D)assigns an integer value to the variable called ptr.
E)None of the above

Question 38

Dynamic memory allocation occurs

A)when a pointer is assigned an incorrect address.
B)when a variable is created at run- time.
C)when a pointer fails to dereference the right variable.
D)when a variable is created by the compiler.
E)None of the above

Question 39

A reason for passing a pointer to a function is

A)to allow the called function to modify a variable accessible to the calling function.
B)to avoid the overhead of copying large data structures.
C)to allow easy access to data in the function that is being called.
D)A and B are both true.
E)None of the above

Question 40

The statement cout << &num1; will output

A)the memory address of the variable called num1.
B)the value stored in the variable called num1.
C)the number 1.
D)the string "&num1".
E)None of the above

Question 41

Any arithmetic operation may be performed on pointers.

Question 42

A pointer can be passed as an argument to a function.

Question 43

The expression s->m has the same meaning as (*s).m.

Question 44

The expression s->m is meaningful only when s is a pointer to a structure and m is a member of the structure.

Question 45

The statement Rectangle * boxPtr; defines a variable boxPtr to be a pointer pointing to a type Rectangle.

Question 46

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

Question 47

C++ does not perform array bounds checking.

Question 48

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

Question 49

An array name is a pointer constant because the address it represents cannot be changed during run- time.

Question 50

Memory cannot be allocated after a program is already running.