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    <p>The correct behavior depends on the declaration of the editMyObject @property. Assuming it is delcared as</p> <pre><code>@property (retain) id editMyObject; //id may be replaced by a more specific type </code></pre> <p>or </p> <pre><code>@property (copy) id editMyObject; </code></pre> <p>then assignment via <code>self.editMyObject =</code> retains or copies the assigned object. Since <code>[[MyObject alloc] init]</code> returns a retained object, that you as the caller own, you have an extra retain of the MyObject instance and it will therefore leak unless it there is a matching release (as in the second block). I would suggest you read the <a href="http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/MemoryMgmt/Articles/MemoryMgmt.html" rel="nofollow noreferrer">Memory Management Programming Guide</a>[2].</p> <p>Your second code block is correct, assuming the property is declared as described above.</p> <p>p.s. You should not use <code>[self.editMyObject release]</code> in a <code>-dealloc</code> method. You should call <code>[editMyObject release]</code> (assuming the ivar backing the @property is called <code>editMyObject</code>). Calling the accessor (via <code>self.editMyObject</code> is safe for @synthesized accessors, but if an overriden accessor relies on object state (which may not be valid at the calling location in <code>-dealloc</code> or causes other side-effects, you have a bug by calling the accessor.</p> <p>[2] Object ownership rules in Cocoa are very simple: if you call a method that has <code>alloc</code>, or <code>copy</code> in its signature (or use <code>+[NSObject new]</code> which is basically equivalent to <code>[[NSObject alloc] init]</code>), then you "own" the object that is returned and you must balance your acquisition of ownership with a <code>release</code>. In all other cases, you do not own the object returned from a method. If you want to keep it, you must take ownership with a <code>retain</code>, and later release ownership with a <code>release</code>.</p>
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    1. POWhy does this create a memory leak (iPhone)?
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    1. USGopalakrishnan Subramanian
    1. USBarry Wark
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POWhy does this create a memory leak (iPhone)?
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    1. This table or related slice is empty.
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      1. This table or related slice is empty.
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      1. This table or related slice is empty.
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    1. COI have an NSMutableArray. I've set it to copy but when I do this [self.List addObject:myobject], I get an uncaught exception. Setting it back to retain works fine. Any suggestions?
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      1. US4thSpace
    2. COI believe that a @property(copy) will use -copy to create the copy, even if the new assignment is a mutable type. Thus you get an immutable copy (you would normally use -mutableCopy to create a mutable copy), causing the exception when you try to mutate the assigned value....
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      1. USBarry Wark
    3. CO[cont'd] You can use @property(retain) and assign like self.List = [[mutableArr mutableCopy] autorelease].
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      1. USBarry Wark
 

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Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

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