One important thing I dont really get.

Im reading "Sams Teach Yourself C++ in 21 days" and Im on day 6 now, but its one simple thing I just dont get.

How do you know when to use like:
int, void, float, double etc etc

There are diffrent things in all examples but I dont get how you know which one to use.

Like:

Code:

---

int MyFunc();
void Myfunc();
//Which to use when?

---

Well does your function return anything useful - like an answer or an error state or not?

If it doesn't return anything useful, then return void.

I mean sometimes the book uses "void function" or "int function" or "unsigned int function".
I dont know whats the diffrence between them all.
Where do I use what?

A function can have a return value. If it doesn't, then it's void. If it has, you need to consider: what does the function return? Is it an integer that can be negative? Then it's int. An integer that cannot be negative? Unsigned int. A floating point number? float or double (double is more precise). A string? Std::string.

The answer comes naturally after looking at the problem.