Understanding C++ compilers from a Java / C# perspective

Question

I\'m a moderately experienced Java / C# programmer, and I\'ve recently started learning C++. The problem is, I\'m having trouble understanding how to structure the various heade

Answer 1

This is something that confused me when I first started using C as well. Books don't do a good job of describing the correct use of headers vs. code files.

The compiler works by loading each .cpp file and compiling it independent of all the others. The first step in compilation is to load all of the headers referred to by #include statements. You can think of it doing a textual insert of the whole foo.h wherever there is a #include "foo.h".

What are the implications of this for how to structure your files? Header files should have whatever parts of the program are needed for other .cpp files to refer to. As a general rule, implementations should not be in header files. This will cause problems. Header files should include declarations of classes, functions, and global variables (if you must use them).