var_glob.c

#include<stdio.h>

/* global variable declaration */
int g;

int main() {

    /* local variable declaration */
    int a,b;

    /* actual initialization */
    a = 10;
    b = 20;
    g = a + b;

    printf("value of a = %d, b = %d and g = %d\n",a ,b, g);

    return 0;
}