title: In iOS, should UIImageView.image be set to "nil" before assigning it a new UIImage?
body: <p>In iOS, should UIImageView.image be set to "nil" before assigning it a new UIImage?</p>
  
  <pre><code>myUIImageView.image = nil;
  
  myUIImageView.image = [UIImage imageNamed:@"talkButton.png"];
  </code></pre>
  
  <p>Would this be the correct way to do it?</p>