Error with multiple definitions of function

Question

I am trying to relearn C++ after taking an intro course a few years ago and I’m having some basic problems. My current problem occurs when trying to use a friend function. H

Answer 1

This problem happen because you are calling fun.cpp instead of fun.hpp. So c++ compile find func.cpp definition twice and throw this error. Pls, change line 3 of your main.cpp file, from #include "fun.cpp" to #include "fun.hpp"