Question

I have “Hello World” code that uses function fhi from another hi.cpp file that has it’s header.

Correct my if my understanding is wrong according following:

I can do include cpp file like #include "c:\c\hi.cpp" instead of using header without any problems except that fact that it looks more readable in header file.

If I include header like sample in my main program hi.h, must hi.h include hi.cpp, or it is done automatically according the same file name hi. I’m wondering how compiler knows where is function fhi body.

Is it possible to have different names for header and cpp files?

Programm:

#include "stdafx.h"
#include "c:\c\hi.h"


int _tmain(int argc, _TCHAR* argv[])
{
fhi(1);
return 0;
}

hi.h

 #include <cstdlib>
 #include <iostream>

 int var;
 int  fhi(int f);

hi.cpp

 #include <cstdlib>
 #include <iostream>

 int  fhi(int f)
 {
 return 0;
 }

Answer 1

must hi.h include hi.cpp

No. hi.h contains only declarations, that can be other by other .cpp files.

I’m wondering how compiler knows where is function fhi body.

It doesn’t. You need to compile all *.cpp files into the object files. In your case, you will have two object files: program.o and hi.o. The linker can now take these two object files, and spit out the executable. References to other functions(in this case the actual definition of fhi(..)) is resolved in this stage.

Also why are you using absolute paths in #includes? It will break when you move the “c” directory around.