Pointers(Engineering > Computer Science And Engineering > C++ Language ) Questions and answers for exam Preparation

Question 1.

What does the following statement mean?

int (*fp)(char*)

pointer to a pointer
pointer to an array of chars
pointer to function taking a char* argument and returns an int
function taking a char* argument and returning a pointer to int

Explanation:-

Answer: Option C. -> pointer to function taking a char* argument and returns an int

pointer to function taking a char* argument and returns an int

Question 2.

Choose the right option

string* x, y;

x is a pointer to a string, y is a string
y is a pointer to a string, x is a string
both x and y are pointer to string types
none of the mentioned

Explanation:-

Answer: Option A. -> x is a pointer to a string, y is a string

* is to be grouped with the variables not the data types.

Question 3. Which of the following is illegal?

int *ip;
string s, *sp = 0;
int i; double* dp = &i;
int *pi = 0;

Explanation:-

Answer: Option C. -> int i; double* dp = &i;

dp is initialized int value of i.

Question 4. The operator used for dereferencing or indirection is ____

*
&
->
->>

Explanation:-

Answer: Option A. -> *

*

Question 5. Which one of the following is not a possible state for a pointer?

hold the address of the specific object
point one past the end of an object
zero
point to a tye

Explanation:-

Answer: Option D. -> point to a tye

A pointer can be in only 3 states a,b and c.

Question 6. The correct statement for a function that takes pointer to a float, a pointer to a pointer to a char and returns a pointer to a pointer to a integer is

int **fun(float**, char**)
int *fun(float*, char*)
int ***fun(float*, char**)
int ***fun(*float, **char)

Explanation:-

Answer: Option C. -> int ***fun(float*, char**)

int ***fun(float*, char**)

Question 7.

What will happen in this code?

int a = 100, b = 200;

int *p = &a, *q = &b;

p = q;

b is assigned to a
p now points to b
a is assigned to b
q now points to a

Explanation:-

Answer: Option B. -> p now points to b

Assigning to refrence changes the object to which the refrence is bound.

Question 8.

What is the output of this program?

#include < iostream >

using namespace std;

int main()

{

int a = 5, b = 10, c = 15;

int *arr[ ] = {&a, &b, &c};

cout

5
10
15
it will return some random number

Explanation:-

Answer: Option D. -> it will return some random number

Array element cannot be address of auto variable. It can be address of static or extern variables.

Question 9.

What is the output of this program?

#include < iostream >

using namespace std;

int main()

{

char *ptr;

char Str[] = "abcdefg";

ptr = Str;

ptr += 5;

cout

fg
cdef
defg
abcd

Explanation:-

Answer: Option A. -> fg

Pointer ptr points to string 'fg'. So it prints fg.

Question 10.

What is the output of this program?

#include < iostream >

using namespace std;

int main()

{

char arr[20];

int i;

for(i = 0; i < 10; i++)

*(arr + i) = 65 + i;

*(arr + i) = '\0';

cout

ABCDEFGHIJ
AAAAAAAAAA
JJJJJJJJ
none of the mentioned

Explanation:-

Answer: Option A. -> ABCDEFGHIJ

Each time we are assigning 65 + i. In first iteration i = 0 and 65 is assigned. So it will print from A to J.