How does program knows about static variable?

Question

We all know that if we declare a static variable in a function then it will be created only once, in next call of the function static variable will not be created and uses its old value.

But my question is, how does our program knows that this variable is created or not?

Answer 1

#include <stdio.h>

void foo()
{
    int a = 10;
    static int sa = 10;

    a

     += 5;
        sa += 5;

        printf("a = %d, sa = %d\n", a, sa);
    }


    int main()
    {
        int i;

        for (i = 0; i < 10; ++i)
            foo();
    }

This prints:

a = 15, sa = 15
a = 15, sa = 20
a = 15, sa = 25
a = 15, sa = 30
a = 15, sa = 35
a = 15, sa = 40
a = 15, sa = 45
a = 15, sa = 50
a = 15, sa = 55
a = 15, sa = 60