MCQ on Pointers in C/C++(Pointers Multiple choice questions)

MCQ on Pointers in C/C++ with answers and explanations for placement tests and job interviews. These solved C Pointers MCQ are useful for the campus placement for all freshers including Engineering Students, MCA students, Computer and IT Engineers, etc.

Our Pointer MCQ ( pointer multiple Choice Questions ) focuses on all areas of the pointers and their concept. We will regularly update the quiz and most interesting thing is that questions come in a random sequence. So every time you will feel new questions.

We have already published a blog post that contains short questions on pointers. If you want you can also see this blog post “Pointer interview questions in C/C++“.

Guideline of Pointers MCQ:

This MCQ on Pointers is intended for checking your Pointers knowledge. It takes 1hours 15 minutes to pass the Pointer MCQ. If you don’t finish the MCQ on Pointers within the mentioned time, all the unanswered questions will count as wrong. You can miss the questions by clicking the “Next” button and return to the previous questions by the “Previous” button. Every unanswered question will count as wrong. MCQ on Pointers has features of randomization which feel you a new question set at every attempt.

In this MCQ on Pointers, we have also implemented a feature that not allowed the user to see the next question or finish the quiz without attempting the current pointer MCQ.

5 votes, 5 avg

You have 1 hours 15 minutes to take the Pointer MCQs

Your time has been Over.

Pointers MCQ

C Programming Multiple Choice Questions And Answers

Pointers MCQ: Pointers Multiple Choice Questions and Answers

1 / 56

Which is an indirection operator among the following?

2 / 56

What is the output of the below code?

#include<stdio.h>

void fun(int **p)
{
  static int q = 40;
  *p = &q;
}

int main()
{
  int data = 27;

  int *ptr = &data;

  fun(&ptr);

  printf("%d", *ptr);

  return 0;
}

Undefined behavior

None of the above

3 / 56

Consider the following snippet of a C program. Assume that swap(&x, &y) exchanges the contents of x and y.

int main()
{
    int array[] = {3, 5, 1, 4, 6, 2};
    int done = 0;
    int i;

    while (done == 0)
    {
        done  = 1;
        for (i = 0; i <= 4; i++)
        {
            if (array[i] < array[i+1])
            {
                swap(&array[i], &array[i+1]);
                done = 0;
            }
        }
        for (i = 5; i >= 1; i--)
        {
            if (array[i] > array[i-1])
            {
                swap(&array[i], &array[i-1]);
                done = 0;
            }
        }
    }

    printf("%d", array[3]);
}

GATE-CS-2017 (Set 2)

The output of the program is _____.

4 / 56

What are the different ways to initialize an array with all elements as zero?

int array[5] = {};

int a = 0, b = 0, c = 0; int array[5] = {a, b, c};

int array[5] = {0};

All of the above

5 / 56

What is the output of the below code?

#include<stdio.h>

int main()
{
    int *ptr;
    
    *ptr = 5;
    
    printf("%d", *ptr);
    
    return 0;
}

Compiler Error

Undefined Behavior

None of the above

6 / 56

What does the following expression mean?

//pointer Quiz

char ∗(∗(∗ a[T]) ( )) ( );

a pointer to a function returning array of T pointers to function returning character pointers.

a function return array of T pointers to functions returning pointers to characters

an array of T pointers to function returning pointers to characters

an array of T pointers to function returning pointers to functions returning pointers to characters.

All of these

7 / 56

What is the output of the below code?

#include<stdio.h>

int main()
{
    int i = 3;
    int *j;
    int **k;
    j = &i;
    k = &j;
    k++;
    printf("%d ",**k);
    return 0;
}

Compiler Error

Run time error.

None of the above

8 / 56

What is the output of the below code?

#include <stdio.h>

int main()
{
    int data = 24;
    int *ptr = NULL;
    int **ptr1 = NULL;
    ptr = &data;
    ptr1 = &ptr;
    printf("%d\n", *ptr );
    printf("%d\n", **ptr1);

    return 0;
}

24, random value

Garbage value, 24

24, 24

None of the above

9 / 56

What is the output of the below code?

#include<stdio.h>

int main()
{
    printf("%u",sizeof(NULL));
    
    return 0;
}

Compiler Error

The size will same as other pointers.

10 / 56

What is the output of the below code?

#include <stdio.h>

int main()
{
    char *pcData="aticleworld";
    printf("%c ",6[pcData]);

    return 0;
}

Compiler Error

11 / 56

What does the following C-statement declare?

//Declaration

int ( * f) (int * ) ;

A function that takes an integer pointer as argument and returns an integer.

A function that takes an integer as argument and returns an integer pointer.

A function that takes an integer pointer as argument and returns a function pointer

A pointer to a function that takes an integer pointer as argument and returns an integer.

12 / 56

Faster access to non-local variables is achieved using an array of pointers to activation records, called a

stack

heap

display

activation tree

13 / 56

What is the output of the below code?

#include "stdio.h"

typedef void (*fPtr)(int);

void display(int a)
{
    printf("%d\n",a);
}

int main()
{
    fPtr fPtr1 = NULL, fPtr2 = NULL;

    fPtr1 = &display;

    fPtr2 = display;

    (*fPtr1)(10);

    fPtr2(10);

    return 0;
}

10 ,10

garbage value, 10

Garbage value, Garbage value,

None of the above

14 / 56

What is the output of the below program?

#include<stdio.h>

int main()
{
    int * ptr = NULL;
    
    printf("%d",*ptr);
    
    return 0;
}

Program will crash.

Undefined behavior

None of the above

15 / 56

What is the output?

#include<stdio.h>

void fun(int *p, int *q)
{
    p = q;
    *p = 2;
}

int main()
{
    int i = 0, j = 1;

    fun(&i, &j);

    printf("%d %d", i, j);

    return 0;
}

0, 2

1, 2

2, 2

0, 1

16 / 56

What does the following ‘C’ statement declare?

//Syntax

int * f [ ] ( );

A function returning a pointer to an array of integers.

A function returning an array of pointers to integers.

Array of functions returning pointers to integers.

An illegal statement.

17 / 56

Which of the following is true with respect to Reference?

A reference can never be NULL

A reference can be reassigned after it is established

A reference needs an explicit dereferencing mechanism

A reference and pointer are synonymous

18 / 56

What is the output of the below code?

#include <stdio.h>

int f(int x, int *py, int **ppz)
{
    int y, z;
    **ppz += 1;
    z  = **ppz;
    *py += 2;
    y = *py;
    x += 3;
    return x + y + z;
}

void main()
{
    int c, *b, **a;
    c = 4;
    b = &c;
    a = &b;
    printf( "%d", f(c,b,a));
    return 0;
}

None of the above

19 / 56

Can we combine the two statements?

char *ptr;

ptr = (char*) malloc(100);

Yes

Depend on platform

None of the above

20 / 56

What is the output of the below code?

#include <stdio.h>

int main(void)
{
    int aiData[5] = {100,200,30,40,50};
    
    int *piData = aiData;
    
    *++piData;
    
    printf("aiData[0] = %d, aiData[1] = %d, *piData = %d", aiData[0], aiData[1], *piData);
    
    return 0;
}

100, 200, 200

200, 100, 200

200, 200, 100

None of the above

21 / 56

What is the output of the below code?

#include<stdio.h>

void fun(int **p)
{
  int q = 40;
  *p = &q;
}

int main()
{
  int data = 27;

  int *ptr = &data;

  fun(&ptr);

  printf("%d", *ptr);

  return 0;
}

Garbage value

Undefined behavior

None of the above

22 / 56

What is the output of the below code?

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
void fun(char** ptr)
{
    ptr++;
}
int main()
{
    char *str = malloc(20*sizeof(char));
    if(str == NULL)
        return -1;

    strcpy(str, "Aticleworld");

    fun(&str);

    puts(str);

    free(str);

    return 0;
}

ticleworld

Aticleworld

icleworld

Garbage value

None of the above

23 / 56

Consider the following C code

int main()
{
    int a = 300;
    
    char *b = (char *)&a;
    
    *++b = 2;
    
    printf("%d ",a);
    
    return 0;
}

Consider the size of int is two bytes and the size of char as one byte. Predict the output of the following code. Assume that the machine is little-endian.

300

556

Compiler Error

None of the above

24 / 56

A function q that accepts a pointer to a character as an argument and returns a pointer to an array of 5 integers can be declared as

int *q(char *)[ 5]

int (*q) (char *)[5]

int (*q (char*) )[5]

None of the above

25 / 56

Assume int is 4 bytes, char is 1 byte and float is 4 bytes. Also, assume that pointer size is 4 bytes (i.e. typical case)

char *pChar;
int *pInt;
float *pFloat;

sizeof(pChar);
sizeof(pInt);
sizeof(pFloat);

What’s the size returned for each of the sizeof() operator?

1 4 8

4 4 4

1 4 4

None of the above

26 / 56

Is there any issue with the below program?

#include "stdlib.h"

int main()
{
    int *ptr1;
    int **ptr2;
    int **ptr3;
    
    ptr1 = (int*)malloc(sizeof(int));
    ptr2 = (int**)malloc(10*sizeof(int*));
    ptr3 = (int**)malloc(10*sizeof(int*));
    
    free(ptr1);
    free(ptr2);
    free(*ptr3);
    
    return 0;
}

Yes

No issue.

27 / 56

calloc(m, n); is equivalent to

ptr = malloc(m*n); strcpy(p, u);

memset(0, m*n);

ptr = malloc (m*n); memset (p, 0, m*n);

All of these

28 / 56

What is the output of the below code?

#include <stdio.h>

int main(void)
{
    int * piData;
    {
        //block
        int Data = 27;
        piData = &Data;
    }
    printf("piData = %d\n", *piData);

    return 0;
}

undefined behavior

Compiler Error

None of the above

29 / 56

Consider the following C function

#include <stdio.h>
int main()
{
char c[ ] = "ICRBCSIT17";
char *p=c;
printf("%s", c+2[p] – 6[p] – 1);
return 0;
}

The output of the program is?

30 / 56

Assume that an int variable takes 4 bytes and a char variable takes 1 byte

#include<stdio.h>

int main()
{
    int arr[] = {10, 20, 30, 40, 50, 60};

    int *ptr1 = arr;
    int *ptr2 = arr + 5;

    printf("%d\n",(ptr2 - ptr1));

    printf("%d\n",(char*)ptr2 - (char*) ptr1);

    return 0;
}

5, 20

20, 5

5, 5

20, 20

Compiler Error

31 / 56

Consider the following table

A. Activation record p. Linking loader
B. Location counter q. Garbage collection
C. Reference counts r. Subroutine call
D. Address relocation s. Assembler

Matching A, B, C, D in the same order gives :

p, q, r, s

q, r, s, p

r, s, p, q

r, s, q, p

32 / 56

‘ptr’ is a pointer to a data type. The expression *ptr++ is evaluated as (in C++) :

*(ptr++)

*(ptr)++

(*ptr++)

None of the above

33 / 56

The reason for using pointers in a C program is

Pointers allow different functions to share and modify their local variables.

To pass large structures so that complete copy of the structure can be avoided.

Pointers enable complex “linked" data structures like linked lists and binary trees.

All of the above

34 / 56

What is the output of the following program?

#include <stdio.h>

void fun(int x)
{
    x = 30;
}

int main()
{
    int y = 20;

    fun(y);

    printf("%d", y);

    return 0;
}

Compiler Error

None of the above

35 / 56

What is the output of the below code?

#include<stdio.h>
int main()
{
    register int data = 10;
    int *ptr = NULL;
    ptr = &data;
    printf("%d ",*ptr);
    return 0;
}

compilation issue.

Garbage value

None of the above

36 / 56

What is the output of the below code?

#include<stdio.h>

void fun(int *p)
{
  int q = 40;
  p = &q;
}

int main()
{
  int data = 27;

  int *ptr = &data;

  fun(ptr);

  printf("%d", *ptr);

  return 0;
}

Garbage value

None of the above

37 / 56

What is the output of the below program?

#include<stdio.h>

int main()
{
    char *ptr = "Aticleworld.com";

    printf("%c\n", *&*&*ptr);

    return 0;
}

Compiler Error

Run time error

Garbage value

None of the above

The operator * is used for dereferencing and the operator & is used to get the address.
These operators cancel out the effect of each other when used one after another.
In the below code, ptr is a pointer to the first character of string A. *ptr gives us A,
&*ptr gives the address of A, *&*ptr again A, &*&*ptr address of A, and finally *&*&*ptr gives ‘A’

int main()
{
    char *ptr = "Aticleworld.com";

    printf("%c\n", *&*&*ptr);

    return 0;
}

Operators in C/C++ language,you must know

int main()
{
    char *ptr = "Aticleworld.com";

    printf("%c\n", *&*&*ptr);

    return 0;
}

Operators in C/C++ language,you must know

38 / 56

What is the output of the below code?

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
    int i;
    int *ptr = (int *) malloc(5 * sizeof(int));
    if(ptr == NULL)
    {
        return -1;
    }
    for (i=0; i<5; i++)
    {
        *(ptr + i) = i;
    }
    printf("%d ", *ptr++);
    printf("%d ", (*ptr)++);
    printf("%d ", *ptr);
    printf("%d ", *++ptr);
    printf("%d ", ++*ptr);

    return 0;
}

0 1 2 2 3

0 1 2 3 3

0 1 2 2 2

None of the above

39 / 56

What will be the output produced by the following C code?

int main()
{
    int array[5][5];

    printf("%d",( (array == *array) && (*array == array[0]) ));

    return 0;
}

Compiler Error

None of the above

40 / 56

Suppose that in a C program snippet, the following statements are used.

i) sizeof(int);

ii) sizeof(int*);

iii) sizeof(int**);

Assuming the size of the pointer is 4 bytes and the size of the int is also 4 bytes, pick the most correct answer from the given options.

Only i) would compile successfully and it would return size as 4.

i), ii) and iii) would compile successfully but the size of each would be different and would be decided at run time.

ii) and iii) would result in compile error but i) would compile and result in size as 4.

i), ii) and iii) would compile successfully and size of each would be same i.e. 4

41 / 56

Consider this C code to swap two integers and these five statements after it:

void swap(int *px, int *py)
{
*px = *px - *py;
*py = *px + *py;
*px = *py - *px;
}

P1: will generate a compilation error P2: may generate a segmentation fault at runtime depending on the arguments passed P3: correctly implements the swap procedure for all input pointers referring to integers stored in memory locations accessible to the process P4: implements the swap procedure correctly for some but not all valid input pointers P5: may add or subtract integers and pointers.

P2 and P3

P2 and P5

P2 and P4

42 / 56

What is the output of the below program? Assume the sizeof an integer and a pointer is 4 bytes.

#include <stdio.h>

int main()
{
    int (*ptr)[5][10];

    printf("%d",  sizeof(*ptr));

    return 0;
}

200

100

None of the above

43 / 56

What is the output of the below code?

int main()
{
    int aiData[5] = {100,200,300,400,500};
    
    int *piData = aiData;
    
    ++*piData;
    
    printf("aiData[0] = %d, aiData[1] = %d, *piData = %d", aiData[0], aiData[1], *piData);
    
    return 0;
}

101 , 200 , 101

200 , 200 , 101

200 , 101, 200

100 , 200 , 101

44 / 56

What is the output of the above program?

#include<stdio.h>

int main()
{
    int a;
    char *x;

    x = (char *) &a;

    a = 512;

    x[0] = 1;

    x[1] = 2;

    printf("%d\n",a);

    return 0;
}

Machine dependent

513

258

Compiler Error

45 / 56

The following statement in ‘C’ declares?

int (*f())[ ];

a function returning an array of pointers to integers.

array of functions returning pointers to integers.

a function returning a pointer to an array of integers.

an illegal statement.

46 / 56

Prior to using a pointer variable, it should be

Initialized

Declared

Both 1 and 2

None of the above

47 / 56

What is the output of the below program? The assumed size of char, int, and double is 1,4,8.

#include<stdio.h>

int main()
{
    int a, b, c;
    char *p = 0;
    int *q = 0;
    double *r = 0;
    
    a = (int)(p + 1);
    b = (int)(q + 1);
    c = (int)(r + 1);
    
    printf("%d %d  %d",a, b, c);
    
    return 0;
}

1, 2, 4

1, 2, 8

1, 4, 8

None of the above

48 / 56

What is the output of the below code?

#include 

int main()
{
    void *ptr;

    ptr = (void*)0;

    printf("%u",sizeof(ptr));

    return 0;
}

Undefined behavior

Compiler Error

size of the void pointer.

None of the above

49 / 56

What is the output of the below program?

#include<stdio.h>

void fun(int arr[])
{
    int i;
    for (i = 0; i < (sizeof(arr)/sizeof(arr[0])); ++i)
    {
        printf("%d ", arr[i]);
    }
}

int main()
{
    int arr[4] = {10, 20,30, 40};

    fun(arr);

    return 0;
}

10, 20

Machine dependent

10 20 30 40

None of the above

statements have the same meaning.

void fun(int arr[])

void fun(int *arr)

So, in the given program, sizeof(arr)/sizeof(arr[0]) contains ratio of pointer size and integer size, this ratio is compiler dependent.

How to pass an array as a parameter in C?

statements have the same meaning.

void fun(int arr[])

void fun(int *arr)

So, in the given program, sizeof(arr)/sizeof(arr[0]) contains ratio of pointer size and integer size, this ratio is compiler dependent.

How to pass an array as a parameter in C?

50 / 56

Consider the following declaration:

int a, *b=&a, **c=&b;

The following program fragment

a=4;

**c=5;

assigns 5 to a

does not change the value of a

assigns the value of b to a

assigns address of c to a

51 / 56

The output of the following program?

#include <stdio.h>

int main()
{
    int *ptr;
    int x;

    ptr = &x;
    *ptr = 0;

    printf(" x = %d\n", x);
    printf(" *ptr = %d\n", *ptr);

    *ptr += 5;
    printf(" x  = %d\n", x);
    printf(" *ptr = %d\n", *ptr);

    (*ptr)++;
    printf(" x = %d\n", x);
    printf(" *ptr = %d\n", *ptr);

    return 0;
}

x = 0 *ptr = 0 x = 5 *ptr = 5 x = 6 *ptr = 6

x = 0 *ptr = 0 x = 5 *ptr = 6 x = 6 *ptr = 5

x = 6 *ptr = 0 x = 5 *ptr = 6 x = 6 *ptr = 6

Compiler Error

None of the above

52 / 56

Below declaration means,

//Declaration

int (*p) [5];

the same as int *p[5];

p is a one dimensional array of size 5, of pointers to integers

Both 1 and 2

p is a pointer to a 5 element integer array

53 / 56

What is the output of the below code?

#include <string.h>
#include <stdio.h>
#include <stdlib.h>

void fun(char** ptr)
{
    (*ptr)++;
}

int main()
{
    char *str = malloc(20*sizeof(char));
    if(str == NULL)
        return -1;
        
    strcpy(str, "Aticleworld");
    
    fun(&str);
    puts(str);
    free(str);
    
    return 0;
}

Aticleworld

ticleworld

Garbage value

Compiler Error

54 / 56

In the below statement, ptr1 and ptr2 are uninitialized pointers to int i.e. they are pointing to some random address that may or may not be a valid address.

//Declaration

int* ptr1, ptr2;

True

False

55 / 56

What is the output of the below code?

#include<stdio.h>

int main()
{
    int data = 27;
    int *ptr = &data;
    
    printf("%u %u", *&ptr, &*ptr);
    
    return 0;
}

Compiler Error

Address of data variable, Address of data variable

Address of pointer, Address of data variable

Address of data variable, Address of pointer

56 / 56

Consider a compiler where int takes 4 bytes, char takes 1 byte and pointer takes 4 bytes.

#include <stdio.h>

int main()
{
    int arr1[] = {1, 2,3};
    int *ptr1 = arr1;

    char arr2[] = {1, 2,3};
    char *ptr2 = arr2;

    printf("sizeof arr1[] = %d ", sizeof(arr1));

    printf("sizeof ptr1 = %d ", sizeof(ptr1));

    printf("sizeof arr2[] = %d ", sizeof(arr2));

    printf("sizeof ptr2 = %d ", sizeof(ptr2));

    return 0;
}

sizeof arr1[] = 3 sizeof ptr1 = 4 sizeof arr2[] = 3 sizeof ptr2 = 4

sizeof arr1[] = 12 sizeof ptr1 = 4 sizeof arr2[] = 3 sizeof ptr2 = 1

sizeof arr1[] = 12 sizeof ptr1 = 4 sizeof arr2[] = 3 sizeof ptr2 = 4

None of the above

Your score is

The average score is 0%

3 comments

Pingback: How to pass an array as a parameter in C? - Aticleworld
kanyakumari says:

June 11, 2021 at 11:14 am

Hi,

#include
int main()
{
char* pcData = “aticleworld”;
printf(“%c”,6[pcData]);
return 0;
}

Output: w

but ans is showing in this MCQ is a

1. Amlendra says:
  
  June 11, 2021 at 5:33 pm
  
  It was wrong. Thanks for the correction. Also, it would be great if you find any issue, then let me know.

Aticleworld

aticleworld offer c tutorial,c programming,c courses, c++, python, c#, microcontroller,embedded c, embedded system, win32 API, windows and linux driver, tips

MCQ on Pointers in C/C++(Pointers Multiple choice questions)

Guideline of Pointers MCQ:

You have 1 hours 15 minutes to take the Pointer MCQs

Your time has been Over.

Recommended Articles for you:

About

3 comments

Leave a Reply Cancel reply

Guideline of Pointers MCQ:

You have 1 hours 15 minutes to take the Pointer MCQs

Your time has been Over.

Recommended Articles for you:

About

You might also like

3 comments

Leave a Reply Cancel reply