Re: Trying to understand -- please help...

FROM : Sherm Pendley
DATE : Wed May 21 22:52:17 2008

On Wed, May 21, 2008 at 3:14 PM, Vijay Malhan <vijay.<email_removed>>
wrote:

> Thanks for the pointers to the documentation. This is sample snippet from
> the documentation.
>
> @implementation MyClass
>
> + (void)initialize
>
> {
>
>    if ( self == [MyClass class] ) {
>
>        /* put initialization code here */
>
>    }
>
> }
>
>
> If I'm not wrong "self" equivalent of "this" which points to an instance
> var.



In a class method, self points to the class object, not to an instance.


> And it is initialized in - init (instance)method.



That makes no sense at all. +initialize a class method, not an instance
method, and it's guaranteed to be called before any other method.


> initialize, it's nil. So does "self" even exist when + initialize is
> called.
> Cuz as per documentation it is the first method called for a Class, before
> +alloc and -init methods are called.
>
> Or the comparison condition in above example is not valid.



The above comparison simply checks "self" against a specific Class object,
so that this +initialize won't have any effect in subclasses.

Once again - you seriously need to take a step back and review the
fundamentals docs. It's a dead-end to try to learn by skipping the
fundamentals, going straight to the references and thinking in terms of
equivalent constructs in Java, C++, or whatever. You need to approach and
learn Cocoa on its own terms.

sherm--

--
Cocoa programming in Perl: http://camelbones.sourceforge.net