title: Objective-C synthesize property name overriding
body: <p>I am trying to understand the purpose of the <code>synthesize</code> directive with property name overriding. Say that I have an interface defined as follow:</p>
  
  <pre><code>@interface Dummy ... {
      UILabel *_dummyLabel;
  }
  
  @property (retain, nonatomic) UILabel *dummyLabel;
  </code></pre>
  
  <p>And in the implementation file, I have:</p>
  
  <pre><code>@synthesize dummyLabel = _dummyLabel;
  </code></pre>
  
  <p>From what i understand, "dummyLabel" is just an alias of the instance variable "_dummyLabel". Is there any difference between self._dummyLabel and self.dummyLabel?</p>