title: To call addChildViewController or not to call addChildViewController
body: <p>I'm fairly new to Objective-C and iOS, and I've taken on an application written by someone else. I noticed something that threw me, and I think my question varies slightly from the other questions people have asked about addChildViewController.</p>
  
  <p>Well, the app works just fine.  Rotations work fine.  Everythings good.
  So what's the problem?</p>
  
  <p>Well there's a full screen view that holds a bunch of subviews in a side-by-side tiled type of layout.  In other words, all of them have the same full screen parent view, and each are siblings to each other.
  Those subviews are each an instance of a <code>UIViewController</code>.
  I had expected to see those subviews set up like this...</p>
  
  <pre><code>DoohickeyController *doohickey = [[DoohickeyController alloc] initWithNibName:@"Doohickey" bundle:nil];
  [self addChildViewController:doohickey];
  [self.view addSubview:doohickey.view];
  </code></pre>
  
  <p>but instead they simply do this....</p>
  
  <pre><code>DoohickeyController *doohickey = [[DoohickeyController alloc] initWithNibName:@"Doohickey" bundle:nil];
  [self.view addSubview:doohickey.view];
  </code></pre>
  
  <p>Is there a hard and fast rule about whether or not to call <code>addChildViewController</code> when the app appears to work just fine?</p>
  
  <p>Is there any advantage/disadvantage to adding the call to <code>addChildViewController</code>?  </p>