Output of C Program | Set 20

Predict the outputs of following C programs.

Question 1

int main()
{
  int x = 10;
  static int y = x;

  if(x == y)
     printf("Equal");
  else if(x > y)
     printf("Greater");
  else
     printf("Less");

  getchar();
  return 0;
}

Output: Compiler Error
In C, static variables can only be initialized using constant literals. See this GFact for details.

Question 2

#include <stdio.h>

int main()
{
  int i;

  for (i = 1; i != 10; i += 2)
  {
    printf(" GeeksforGeeks ");
  }

  getchar();
  return 0;
}

Output: Infinite times GeeksforGeeks

The loop termination condition never becomes true and the loop prints GeeksforGeeks infinite times. In general, if a for or while statement uses a loop counter, then it is safer to use a relational operator (such as <) to terminate the loop than using an inequality operator (operator !=). See this for details.

Question 3

#include<stdio.h>
struct st
{
    int x;
    struct st next;
};

int main()
{
    struct st temp;
    temp.x = 10;
    temp.next = temp;
    printf("%d", temp.next.x);

    getchar();
    return 0;
}

Output: Compiler Error
A C structure cannot contain a member of its own type because if this is allowed then it becomes impossible for compiler to know size of such struct. Although a pointer of same type can be a member because pointers of all types are of same size and compiler can calculate size of struct.

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