Help with inheritance

[Sirrius]

I am trying to do some simple inheritance with a few classes but keep running into an error at compile time. It is error C2504, 'undefined base class'. What does this mean. My classes are defined, I think they are anyway. This is what it looks like.

class a{

};

class b : public a{

};

I am including the files as well. I am just kind of stumped. Thanks Brian.

[Jose Cezar S Ynion]

Make sure you include the header file of your base class in your derived class. 1. say you defined class a in "a.h" file class a { }; 2. In class b header file #include "a.h" class b: public a { }; Jose Cezar S. Ynion