return value

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int f1(int x, int y){
    return x+y;
}

int f2(int x){
    return ++x;
}

int f3(int x){
    return x++; /*  postfix version, return value will not be incremented,
                    use the prefix version to increment before returning, ++x
                    example f2()
                */
}

int f4(int x){
    x++;
    int y = x;
    return y;
}

int main (int argc, char **argv){

    int a,b;

    a = 1;

    b = 2;

    printf("f1: %d\n",f1(a,b));
    printf("f2: %d\n",f2(a));
    printf("f3: %d\n",f3(a));
    printf("f4: %d\n",f4(a));

    return 0;
}

/*
 output:

f1: 3
f2: 2
f3: 1
f4: 2


 */