func_call.c

#include<stdio.h>

/* function declaration */
int max(int num1, int num2);

int main() {

    /* local vaariable definiton */
    int a = 100;
    int b = 200;
    int ret;

    /* calling a function to get the max value */
    ret = max(a,b);

    printf("Max value is : %d\n", ret);

    return 0;
}

/* function returning the  max between two numbers */
int max(int num1, int num2) {

    /* local variable declaration */
    int result;

    if(num1 > num2)
      result = num1;
    else
      result = num2;

    return result;
}