C Data type - void

Linguistic meaning of void is nothing. Size of void data type is meaningless question.

What will be output of following c code?
#include<stdio.h>
int main(){
    int size;
    size=sizeof(void);
    printf("%d",size);
    return 0;
}

Output: Compilation error

If we will try to find the size of void data type complier will show an error message �not type allowed�. We cannot use any storage class modifier with void data type so void data type doesn�t reserve any memory space. Hence we cannot declare any variable as of void type i.e.
void num;   //compilation error

Use of void data type

1. To declare generic pointer
2. As a function return type
3. As a function parameter.