Senario:
There are two source files a.cpp and b.cpp both in a project. a.cpp includes a function called viod show(). Now I wanna invoke that function in b.cpp.
As I know, there are two ways we can use to invoke a function from another .cpp source file:
1. In b.cpp, use "extern void show()" statement to declare an extern function.
2. add a new header file(we call a.h for example), in that header file, we declare that function we want other source files to see and use by adding these codes:
then, we need to add "include "a.h"" statement at the beginning of b.cpp, after "include <iostream>" statement. After that, we can invoke show() in b.cpp now.
PS: there is no restriction about the name of the header file, I use "b.h" as its name here is just to say that the function included in it is defined in a.cpp file.
PPS: Does anyone know the differences between these two methods?