Answers for "what is .h file in cpp"

what is a header in c++

// my_class.h
#ifndef MY_CLASS_H // include guard
#define MY_CLASS_H

namespace N
{
    class my_class
    {
    public:
        void do_something();
    };
}

#endif /* MY_CLASS_H */

what is a header in c++

// my_class.h
namespace N
{
    class my_class
    {
    public:
        void do_something();
    };

}

check .h files syntax c++

g++ -c myheader.h