Why does it throw a Segmentation fault when declaring a simple variable?

Question

C++ / C#

#include <stdio.h>

int main()
{
    int a;
    a = 21312;
    printf(a);
    return 0;
}

Answer 1

Because you have not even mastered the conclusion. Must beprintf("%d\n", a);

Answer 2

Because it's nonsense.
printf()