C Language

#include <stdio.h>  

void change(int,int);  

int main()  

{  

    int a=15,b=16;  

    change(a,b); 

    printf("Value of a is: %d",a);  

    printf("\n");  

    printf("Value of b is: %d",b);  

    return 0;  

}  

void change(int x,int y)  

{  

    x=13;  

    y=17;  

} 

What will be the output:-

• Value of a is: 15 Value of b is: 16

• Value of a is: 13 Value of b is: 17

• Value of a is: 16 Value of b is: 15

• Value of a is: 17 Value of b is: 13

Correct way to initialize an array in C programming Language is:-

• int num[6] = { 1, 2, 3, 4, 5};

• int num[6] = { 1, 2, 3, 16, 25, 45, 9 };

• int a={};

• int x{3}={2,3,4};

The correct output of given code snippet is:-

#include<stdio.h>

void main()

{

int a[5]= {1,2,1,4,9};

int i, j, k;

i= ++a[1];

j= a[1]++;

k= a[1++];

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

}

• 3, 4, 1

• 2, 2, 9

• 4, 3, 4

• 3, 3, 1

The correct Code to swap two numbers in C language without using a third variable is:-

• #include<stdio.h>

  int main()

  {

  int a=10, b=20;

  printf("Before swap a=%d b=%d",a,b);

  a=a-b;

  b=a-b;

  a=a+b;

  printf("\nAfter swap a=%d b=%d",a,b);

  }

• #include<stdio.h>

  int main()

  {

  int a=10, b=20;

  printf("Before swap a=%d b=%d",a,b);

  a=a+b;

  b=a+b;

  a=a-b;

  printf("\nAfter swap a=%d b=%d",a,b);

  }

• #include<stdio.h>

  int main()

  {

  int a=10, b=20;

  printf("Before swap a=%d b=%d",a,b);

  a=a+b;

  b=a-b;

  a=a+b;

  printf("\nAfter swap a=%d b=%d",a,b);

  }

• #include<stdio.h>

  int main()

  {

  int a=10, b=20;

  printf("Before swap a=%d b=%d",a,b);

  a=a+b;

  b=a-b;

  a=a-b;

  printf("\nAfter swap a=%d b=%d",a,b);

  }

The correct output of given code snippet is:-

#include<stdio.h>

int main()

{

int x=5;

printf("%d", x<<1);

return 0;

}

• 0

• 5

• 10

• 1

Answer explanation

The bitwise left shift operator(<<) shifts all bits towards the left by a certain number of specified bits. The expression x<<1 always returns x*2

Which code snippet will be executed faster:-

a) #include<stdio.h>

int main()

{

int x=5;

printf("%d", x++);

return 0;

}

b)#include<stdio.h>

int main()

{

int x=5;

printf("%d", x+=1); // same as x=x+1

return 0;

}

• Only b

• Only a

• Both will take same time

• It depends on compiler

Answer explanation

x++ being a unary operation, it just needs one variable. Whereas, x = x + 1 is a binary operation that adds overhead to take more time.

During function call, Default Parameter Passing Mechanism is called as

• Call by Reference

• Call by Address

• Call by Name

• Call by Value

Which is the correct syntax to declare constants in C?

• int const var = 10;

• None

• const int var = 10;

• Both A and C

The output of given code snippet is:-

#include <stdio.h>

void main()

{

char *a[10] = {"hi", "hello"};

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

}

• 10

• 80

• Run time error

• 70

Answer explanation

The size of pointer is 8 bytes on a 64 bit system. For the given array a of 10 elements, it will be 8×10 = 80 bytes. Which is also 4 bytes on a 32 bit system.

The correct output of given code snippet is:-

#include <stdio.h>

int main()

{

int a=76;

int *ptra = &a;

printf("%d\n", *ptra);

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

return 0;

}

• 293242-e

  76

• 76

  76

• Compilation Error

• 100110101

  76