Amazon.com Widgets dealloc question
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+ Official Forum for Programming in Objective-C (the iPhone Programming Language) - Stephen Kochan
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sir
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on: March 15, 2009, 10:02:04 PM

Hey Steve,

I was wondering about your dealloc example in Chapter 8.  Since
-(void) dealoc {
       [origin release];
       return [super dealloc];
}

is a method in the Rectangle class, do we need to call that method in main to make it work?

Is this some special method that does not need to be called to happen?

Also, I do not understand how synthesizing the accessor methods has an effect on dealloc.


Thanks for your help as always,
Nicholas
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skochan
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Reply #1 on: March 16, 2009, 05:43:06 AM

Remember (see the note on p. 179) that the dealloc method is called automatically by the system when the space for an object is to be destroyed.  This normally happens after you release the object.  (As you'll learn in later chapters, dealloc will not be called if the object is referenced someplace else in the program).

For your second question, if you specify either the retain or copy attributes in your @property declaration, the synthesized accesor method will automatically release the old value of the instance variable in the setter method.    As noted in the previous paragraph, this may end up invoking the dealloc method.

Cheers,

Steve
Last Edit: March 16, 2009, 05:45:39 AM by skochan Logged
sir
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Reply #2 on: March 16, 2009, 09:09:39 PM

OK, I see.  It appears that you go further into detail with retain or copy in the Memory Management chapter.
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