Re: How is this possible?

FROM : Jonathan del Strother
DATE : Sun Apr 20 17:32:21 2008

On Sun, Apr 20, 2008 at 4:25 PM, Don Arnel <<email_removed>> wrote:
> I have two different class objects that need to know about each other (see
> below). But if I include the header from one class inside the header of the
> other class the compiler complains. Is this even possible?
>
>  ClassOne.h:
>  ----------------
>
>  #import "ClassTwo.h"
>
>  @interface ClassOne : NSObject {
>
>        ClassTwo *objectTwo;
>  }
>
>  @end
>  ----------------
>
>
>  ClassTwo.h:
>  ----------------
>
>  #import "ClassOne.h"
>
>  @interface ClassTwo : NSObject {
>
>        ClassOne *objectOne;
>  }
>
>  @end




Pre-declare the classes with '@class' - eg

@class ClassTwo;
@interface ClassOne : NSObject {

      ClassTwo *objectTwo;
}

@end

You'll still need to import 'ClassTwo.h' in your implementation file.

It's a good idea to do that instead of importing any of your own
headers within header files.  Things can get a bit contorted
otherwise.