I Wrote a class which includes an pointer to the next Object of the same class. It worked fine. Then i tried to place the class in it's own header h. + .cpp file. Now when i'm trying to compile, i'm getting the following error:(I'm Using Dev cpp)

`NULL' undeclared (first use this function)

(I'm using NULL in the constructor for the pointer to the next Object)

I would venture the following guess. One of the .cpp files that includes the .h file includes it before including anything else (like <stdlib.h> and so forth). You should include your standard library headers first.

You could just do:

#ifndef NULL
#define NULL 0
#endif

Radagar: NULL is declared in standard header files. I'm not sure why .h -> .hpp would do anything at all ... it sounds silly.

Yeah, I was about to link that
Almost certianly, that's his problem.

I know both these things, I've read the link (before reading this thread, actually), and your post has no relevance whatsoever to what you quoted.

NULL is declared in <stddef.h> under C and <cstddef> under C++.