unknown type name in objective c

Question

I\'m pretty new to objective c, and having some basic problems.

I wrote a simple program using a navigator, and everything worked fine. then I added few lines of cod

Answer 1

I figured out, that the same error appears if you have an import-cycle:

Class_A.h: #import "Class_B.h"

Class_B.h: #import "Class_A.h"

To fix: look for any imports of the offending class (the error tab is your friend, expand the relevant error for a list of imports). Remove #import's accordingly