title: Difference between _ and self. in Objective-C
body: <p>Is there a difference between using the underscore and using the <code>self</code> keyword in Objective-C when calling an <code>@property</code>?</p>
  
  <p>Property declaration:</p>
  
  <pre><code>@property (weak, nonatomic) NSString *myString;
  </code></pre>
  
  <p>Calling <code>@synthesize</code> on the property:</p>
  
  <pre><code>@synthesize myString = _myString;
  </code></pre>
  
  <p>Is there a difference if I want to use it in my code? When? In the getter/setter?</p>
  
  <pre><code>self.myString = @"test";
  _myString = @"test";
  </code></pre>