title: Why is self.navigationController null in viewDidLoad?
body: <p>I know there are a lot of similar questions, but I can't find one that specifically addresses this.</p>
  
  <p>Why is <code>self.navigationController</code> null when called in <code>viewDidLoad</code>, but correct when called from outside <code>viewDidLoad</code>?</p>
  
  <p>This is my output from <code>NSLog(@"%@",self.navigationController);</code> The first is called in <code>viewDidLoad</code>, the second I add a button to the interface with a method that calls <code>NSLog(@"%@",self.navigationController);</code>:</p>
  
  <pre><code>NavApp[31524:11003] (null)
  NavApp[31524:11003] &lt;UINavigationController: 0x6e21190&gt;
  </code></pre>
  
  <p>I know there must be some simple explanation for this behavior, I'm just curious as to what it is.  Thanks!</p>