test

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <stdint.h>

void changeVar(int *a);

int main(int argc, const char *argv[]) {
    int x = 100;
    printf("x is: %d\n", x);
    changeVar(&x);
    printf("x is: %d\n", x);

    return 0;
}

void changeVar(int *a)
{
    *a = 20;
}

/*
out:

x is: 100
x is: 20


*/