I dont quite understand this Diagram

[Anmol444]

This Diagram: http://i40.tinypic.com/i57oz6.png

I dont understand why Class Function Definitions, Class Definition and Global Constants are repeated...

Can anyone please explain?

Also what does it even mean Global Constant? How can a global constant exist inside a header?

[Bourgond Aries]

I've been programming for quite a while and I think I have a fair grip on C++, but I don't understand this diagram either. Perhaps it was shipped with some other literature.

a global constant in a header:

extern const float pi;

in some .cpp file...

const float pi = 3.14;

[Anmol444]

what does extern represent?

[Bourgond Aries]

I think it tells the compiler that the definition of the variable is in another compilation unit. The linker should resolve it.

[Anmol444]

O ok, thanks :D