functions.cpp

int main() {
    // So this is my main function
    // it gets called automatically, but otherwise its no different then any other function
    
    int number_of_tates = 0; // I take inspiration from my enviroment ;)
    
    number_of_tates = work_on_song(number_of_tates); // Now I'm going to call my function, which I define down below.
                                                     // It takes an integer, the old amount, and returns an integer (the new amount).
                                                     // After calling the function, I assign it to the variable "number_of_tates",
                                                     // overwriting the old value.
    cout << number_of_tates << end; // prints '3'
    
    number_of_tates = work_on_song(number_of_tates);
    number_of_tates = work_on_song(number_of_tates);
}

int work_on_song(int n) { 
    return n + 3;
}

// To be exceedingly pedantic, this code won't compile as is. Because of historical reasons, 
// C++ functions need to be declared above where you want to use them.