function problems

alright, i have a function declared as void, and what it does, it prints stuff out to the screen, now whenever i call this function, i get this error:
implicit declaration of function `int swap(...)'

what the hell does that mean? i copied it directly out of my book

post the code.

Code:

---


#include <iostream.h>
#include <stdlib.h>

int main()
{
int x = 5, y=10;
cout <<"Main. Before swap, x: " <<x<<" y: "<< y<< "\n";
swap(x,y);
cout <<"Main. After swap, x: "<<x<<" y: "<<y <<"\n";
return 0;
}

void swap(int x, int y){
int temp;
    cout "Swap. Before swap, x: " << x << " y: "<< y<< "\n";

    temp = x;
    x = y;
    y = temp;

    cout << "Swap. After swap, x: "<<x<<" y: "<<y<< "\n";

}

---

You are using a function before it has been declared. Above main add this line.....

void swap(int,int);

This is called a function prototype and tells the compiler the functions return type and parameter list.

You can also place the function before main() but with too many functions this can get ugly.