What is this?

>warning: conflicting types for 'something' [enabled by default]

If put the main after the functions this doesn't show up, why?

If you try to call the function before it's declared the compiler will have to guess its types.

You can put just the declaration above main() and put the definition below.



int dicks(int x);

int main(int argc, char **argv){
    if(argc < 2){
        return 1;
    }

    printf("Dicks! :%d\n", dicks(atoi(argv[1])));

    return 0;
}

int dicks(int x){
    int i;
    int j = 0;

    for(i=0; i<x; ++i){
        j += x % i;
    }

    return j;
}

>>2
Put why put main() first then?

>>2
Specifically, for compatibility with K&R C, any function that is used before a declaration is seen is silently assumed to have type int(int). As I recall, strict compatibility with C99 requires that this behavior be deprecated.

>>3
There are different styles. It is very common for C sources to put leaf functions first and leave main at the end, but not everyone prefers it. If you have functions that call one another, it will of course be impossible to avoid prototyping at least one of them.