C Advanced Pointer

Question 1

C

void fun(int *p) 
{ 
  int q = 10; 
  p = &q; 
}     
  
int main() 
{ 
  int r = 20; 
  int *p = &r; 
  fun(p); 
  printf(\"%d\", *p); 
  return 0; 
}

• 10

• 20

• Compiler error

• Runtime Error

Question 2

Assume sizeof an integer and a pointer is 4 byte. Output?

C

#include <stdio.h>

#define R 10
#define C 20

int main()
{
   int (*p)[R][C];
   printf(\"%d\",  sizeof(*p));
   getchar();
   return 0;
}

• 200
• 4
• 800
• 80

Question 3

C

#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;
}

• 2 5
• Garbage Value
• Compiler Error
• Segmentation Fault

Question 4

C

#include <stdio.h>

char *c[] = {\"GeksQuiz\", \"MCQ\", \"TEST\", \"QUIZ\"};
char **cp[] = {c+3, c+2, c+1, c};
char ***cpp = cp;

int main()
{
    printf(\"%s \", **++cpp);
    printf(\"%s \", *--*++cpp+3);
    printf(\"%s \", *cpp[-2]+3);
    printf(\"%s \", cpp[-1][-1]+1);
    return 0;
}

• TEST sQuiz Z CQ
• MCQ Quiz Z CQ
• TEST Quiz Z CQ
• GarbageValue sQuiz Z CQ

Question 5

Predict the output

C

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

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

int main()
{
    char *str = (void *)malloc(100*sizeof(char));
    strcpy(str, \"GeeksQuiz\");
    fun(&str);
    puts(str);
    free(str);
    return 0;
}

• GeeksQuiz
• eeksQuiz
• Garbage Value
• Compiler Error

Question 6

Assume that the size of int is 4.

C

#include <stdio.h>
void f(char**);
int main()
{
    char *argv[] = { \"ab\", \"cd\", \"ef\", \"gh\", \"ij\", \"kl\" };
    f(argv);
    return 0;
}
void f(char **p)
{
    char *t;
    t = (p += sizeof(int))[-1];
    printf(\"%s\\n\", t);
}

• ab
• cd
• ef
• gh

Question 7

• 2 3 5 6

• 2 3 4 5

• 4 5 0 0

• none of the above

Question 8

C

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

int main(void)
{
    int i;
    int *ptr = (int *) malloc(5 * sizeof(int));

    for (i=0; i<5; i++)
        *(ptr + i) = i;

    printf(\"%d \", *ptr++);
    printf(\"%d \", (*ptr)++);
    printf(\"%d \", *ptr);
    printf(\"%d \", *++ptr);
    printf(\"%d \", ++*ptr);
}

• Compiler Error
• 0 1 2 2 3
• 0 1 2 3 4
• 1 2 3 4 5

Question 9

Output of following program

C

#include <stdio.h>
int fun(int arr[]) {
   arr = arr+1;	
   printf(\"%d \", arr[0]);
}
int main(void) {
   int arr[2] = {10, 20};
   fun(arr);
   printf(\"%d\", arr[0]);
   return 0;
}

• Compiler Error
• 20 10
• 20 20
• 10 10

Question 10

What is printed by the following C program?

C

$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));
   getchar();
}

• 18
• 19
• 21
• 22