C++ function prototypes?

Question

Here goes newbie question number 5, but I don\'t have a teacher.. so.. anyhow here we go:

I\'m wondering if is necessary to have function prototypes at the top of the fi

Answer 1

This declares but does not define the function say_hi:

void say_hi();

This both declares and defines the function say_hi:

void say_hi(){
    std::cout << "hi" << std::endl;
}

You can declare a function many times; you can only define it once.

A function must be declared in the file before you can call it. A function must be defined somewhere--in the same file before or after you call it or maybe even in a different file.

So, yes, this is perfectly fine.