@class keyword usage

[iphonegamedeveloper]

Hi,


What is the use of @class keyword?When we want to use that keyword?Thanks

[Bertrand21]

You always #import the files you're using in your implementation, and if you need to reference a class in your header file use an @class forward declaration.

[Kalimba]

Originally Posted by Bertrand21

You always #import the files you're using in your implementation, and if you need to reference a class in your header file use an @class forward declaration.

This is a partially correct description.

The @class keyword is used to forward declare a class. You are not required to #import the files needed in an implementation (IOW, you might be able to use the @class notation in an implementation). Also, if you need to reference a class in another header file, you aren't required to use the @class notation (IOW, you can also simply #import the class header in your header file).

There's no actual need for using the @class keyword. It's basically a way to tell the compiler about the existence of a class, without bothering the compiler with all of the details of that class' implementation. Of course, you can only do this in places where the details of a class are insignificant.

I'm sure there could be a great debate as to why/when/how it should be used, but my experience and personal practice is to use forward declarations wherever possible to save a bit of compile time.