Re: Sending a Selector to another Class.
Re: Sending a Selector to another Class.
- Subject: Re: Sending a Selector to another Class.
- From: Joshua Garnham <email@hidden>
- Date: Thu, 22 Oct 2009 05:52:37 +0000 (GMT)
Ah, I see. so I need to send it to an instance of the class not the class it self.
How would I do that?
Thanks,
Josh.
________________________________
From: Jens Alfke <email@hidden>
To: Jim Kang <email@hidden>
Cc: Joshua Garnham <email@hidden>; email@hidden
Sent: Thursday, 22 October, 2009 6:21:29
Subject: Re: Sending a Selector to another Class.
On Oct 21, 2009, at 9:43 AM, Jim Kang wrote:
That selector is a unique index that points to a method of a specific class.
>
No, that's not true of Objective-C (although it is of C++ method-pointers.) A selector is, basically, just a unique string: it defines a message, not a method, to use the old Smalltalk OOP terminology. Any class that implements a method with that name uses the same selector for it, regardless of inheritance.
To be specific, if I create two unrelated classes A and B, each of which implements a -foo method, the selector @selector(foo) is used for both.
Joshua's problem was, apparently, that he was trying to send an message to a class object instead of an instance, but the corresponding method was defined on instances, not the class.
—Jens
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