objective c - No visible @interface for

Question

I have gotten this error on several occasions and am unclear as to what causes the error in general. After looking for over an hour on stack overflow and google I still don't have an answer. Could someone help?

I've seen several specific answers but nothing that says why the error happens, only "do x", or "do y".

I haven't included code yet because I want to know the reason that this error happens in general so I can fix my code in the future whenever I get this error.

Answer 1

There are lots of reasons it could happen, but generally it's saying that at the line of code it flags, it doesn't see any evidence that the selector you are referencing is in the interface of the type it thinks the object has.

In this example,

No visible interface error

They declared operandStack with the wrong type.

In this one

http://www.raywenderlich.com/forums/viewtopic.php?f=2&t=3312

They had a typo in the selector name