C Programming Language Question Bank

C Programming Language Question Bank -


This is a Constantly Updated Question Bank of C Programming Language. It aims to cover easy as well difficulty and tricky C Programming Questions from all possible topics. 
Also C/C++ questions are often asked in interviews, so these questions can also come handy in preparing for C/C++ Interview Questions.

One or More question will be added each day.

Question 1. 

Determine the output of the following code?

int  main ()

{
  char far *p1,*p2;
  printf ( " p1 : %d  \n\n  p2 : %d", sizeof (p1), sizeof(p2));
  return 0;
}

-> Solution

Question 2. 

Guess the output of the following code?

int  main ()

{
  printf ( "%lf", (0.99 - 0.9 -0.09);
  return 0;
}

-> Solution

Question 3. 

What will be the output of the following code and why?

int main()
{
  unsigned int y = 12;
  int x = -2;
  
   if(x>y)
     printf   ("x is greater");
  else
     printf ("y is greater");
  
return 0;
}

-> Solution

Question 4. 

Write a program to find and print the given number is odd or even, Using only one printf (output) statement, no conditional Statement and no logical,relational and arithmatic operators.

-> Solution

Question 5. 

Predict  the output of the following code and why?

#include <stdio.h>

int main()
{
  int i=012;
  int j=046;
  int   k=056;
  printf("i=%d",i);
  printf("j=%d",j);
  printf("k=%d",k);
  return 0;
}

-> Solution

Question 6. 

Write a program to print "HI",  without any semi colon.

-> Solution

Question 7. 

What will be  the output of the following code and why?

#include <stdio.h>

int  main()
{
  int x,y;
  x = 5;
  y = ++x *   ++x;
  printf("value of x = %d and value of y = %d\n",x,y);
 return 0;
}

-> Solution

Question 8. 

Consider the following C source code and guess its output?

int counter (int value)  
{    
 static int count =0;    
 count = count +value;;    
 return count; 
 }  

int main()  
{   
  int i , j;      
  for (i=0; i <=5; i++)     
    j = counter(i);
 printf ("J = %d", j);
 return 0;
 }

-> Solution


Question 9. 

What will be output of this C Code Snipet?

#include<setjmp.h>
#include<stdio.h>
  
static jmp_buf  buf;    

int main()  
{    
 volatile  int b;    
 int a;
 b =3;
 a = 3; 
 if(setjmp(buf)!=0)      
   {      

      printf("A = %d ", a);        
      printf("\n\nB = %d ", b);        
      exit(0);    
   }    
  b = 5;
  a = 5;    
 longjmp(buf , 1);  
 return 0;
}

-> Solution

Question 10. 

Write a program to multiply two number without using any arithemetic operators (*,+,-,/,%) in C.

-> Solution


Question 11. 

What will be  the output of the following code and why?

#include <stdio.h>

struct data    
   {       
      int a;      
      int b;      
      int c;          
   };    
 
int main()  
{    
  
 struct node  s= { 3, 5,6 };     

struct node *pt = &s;    
printf("%d" ,  *(int*)pt);  

return 0;
}

-> Solution


Question 12. 

What is the aritmetic operation performed by function on x in relation with n?

int  mystery ( int x , int  n)  
{    


  int val;    
  val =1;        
  if (n>0)     
   {      
     if (n%2 == 1)  
     val = val *x;            
     val = val * mystery(x*x , n/2);    
   }    
return val;

}

-> Solution


Question 13. 

What will be  the output of the following code?

#include <stdio.h>

int main()  
{    
  int  a[5] = {1,2,3,4,5};    
  int *ptr =  (int*)(&a+1);      
 printf("%d %d" , *(a+1), *(ptr-1) );   
 return 0;
 }

-> Solution


Question 14. 

Output of this program will be?

#include <stdio.h>

void function(int [][3] );         

int main()  
{    
  int a [3][3]= {  { 1,2,3} ,  { 4,5,6} , {7,8,9} };    
  function(a);    
  printf("%d" , a[2][1]); 
  return 0;
 }    

void function ( int b [ ] [3] ) 
  {    
     ++ b;   
      b[1][1] =9; 
  }

-> Solution

Question 15. 

State  the output of the following code.

#include <stdio.h>

int main()  
{    

  int a, b,c, d;    
  a=3;    
  b=5;    
  c=a,b;    
  d=(a,b);      
  printf("c = %d" ,c);    
  printf("\n\nd = %d" ,d);    
  return 0;
}

-> Solution


Question 16. 

What will be  the output of the following code and why?

#include <stdio.h>

int main()
{
  int x = 40;
   {
      int x = 20;
      printf ("%d ", x);
   }
printf ("\n\n%d",x);

}

-> Solution

Question 17. 

What will be  the output of the following code?

#include <stdio.h>

int main()  
{    

  int a[][3] = { 1,2,3 ,4,5,6};    
  int (*ptr)[3] =a;      
  printf("%d\n\n %d "  ,(*ptr)[1], (*ptr)[2] );      
  ++ptr;    
  printf("\n\n%d\n\n%d"  ,(*ptr)[1], (*ptr)[2] );  
  return 0;
}

-> Solution


Question 18. 

Which functions of the below  3 functions misuses pointers and why?

int *f1(void)  
 {    
   int x =10;    
   return(&x);  
 }    

int *f2(void)  
 
{    
    int*ptr;    
    *ptr =10;    
    return ptr;  
 }    

int *f3(void)  

{    
  int *ptr;    
  ptr=(int*) 
  malloc(sizeof(int));    
  return ptr;  
}

-> Solution

Question 19. 

Guess  the output of the following code.

#include <stdio.h>

int main()  
{   

   int i=3;    
   int j;     
   j = sizeof(++i+ ++i);     
  printf("i=%d j=%d", i ,j); 
  return 0;
 }

-> Solution

Question 20. 

What will be  the output of the following code and why?

#include <stdio.h>

void f1(int *, int);   
void f2(int *, int);   
void(*p[2]) ( int *, int);  

int  main()  
{    
  int a;    
  int b;      
  p[0] = f1;   
  p[1] = f2;   
  a=3;    
  b=5;     
  p[0](&a , b);    
  printf("%d\t %d\t" , a ,b);     
  p[1](&a , b);   
  printf("%d\t %d\t" , a ,b); 
 }   

void f1( int* p , int q)  

{   
   int tmp;    
   tmp =*p;    
   *p = q;    
   q= tmp;  
}    

void f2( int* p , int q)  
{    
   int tmp;    
   tmp =*p;    
   *p = q;    
    q= tmp;  
}

-> Solution

Question 21. 

Output of the following code will be?

#include <stdio.h>

void e(int );      

int main( ) 
 {   
     int a;    
     a=3;    
    e(a); 
   return 0;
 }    

void e(int n)  
{    
   if(n>0)   
      {     
         e(--n);      
         printf("%d" , n);      
         e(--n);   
       }  
}

-> Solution

Question 22. 

What will be  the output of the following code?

#include <stdio.h>

#define ASS Donkey

int main()
{
printf ("ASS");
return 0;
}

-> Solution

Question 23. 

What is the type of temp below?

typedef int (*test) ( float * , float*) 
 test tmp;

-> Solution

Question 24. 

Determine  the output of the following code.

#include <stdio.h>

void f(char**);    

main() 
 {   
      char * argv[] = { "ab" ,"cd" , "ef" ,"gh", "ij" ,"kl" };    
      f( argv ); 
 }    

void f( char **p )  
{   
   char* t;     
    t= (p+= sizeof(int))[-1];     
    printf( "%s" , t);  
}

-> Solution

Question 25. 

Determine  the output of the following program.

#include<stdarg.h>  

int ripple ( int , ...);    

int main()  
{    
  int num;    
  num = ripple ( 3, 5,7);    
  printf( " %d" , num);  
  return 0; 
}    

int ripple (int n, ...)  
{    
  int i , j;    
  int k;      
  va_list p;      
  k= 0;    
  j = 1;    
  va_start( p , n);           
  for (; j<n;  ++j)     
   {      
     i =  va_arg( p , int);      
     for (; i;    i &=i-1  )        
     ++k;    
   }    
return k;  
}

-> Solution


Question 26. 

Predict  the output of the following code.

#include <stdio.h>

int main()  
{    
 char *p;    
 char buf[10] = { 1,2,3,4,5,6,9,8} ;    
 p = (buf+1)[5];    
 printf("%d" , p);  
}

-> Solution

Collected By Anuj Pathania

  Acknowledgements