Why should I use function prototypes?

[Zeikko]

C# really pissed me off so I decided to return to learn C++. However, I really don't get why I should use function prototypes. Is there any real reason, or is only to make sure that you don't make mistakes in the real function?

Thanks.

[Bazzy]

So that the compiler can check whether you are passing the right arguments and resolve overloading.

[Moschops]

You do not have to use prototypes; so long as you define the function before you use it, it will work.

In addition to Bazzy's words, if you ever want to use a function that you did not write and are not going to be compiling yourself (which I expect is very, very often), the compiler must still know what will be passed in and what will be returned.

[Intrexa]

Function a calls function b
Function b calls function a


You would need to use a prototype in that situation, no way that I know of around it.