Do I have to include the composition class's header file in the main. cpp

Answer 1

Yes if you are working with more than one file:
#include <iostream>
# include yourfile.h //your header file here
using namespace std;
Somthing like that

Answer 2

Oh.
It should not be necessary to include that header file.
but if the header file is written correct there is no harm in including it different places
by correct i mean that it has a (#ifndef header #define header) intro

Answer 3

But my question is if you have another class inside the class your file do I need to include that class header file or not?

Answer 4

Thank you