title: Appending string to UILabel text?
body: <p>I'm starting to develop for the iPhone. I have a beginner-type question, I'm sure:</p>
  
  <p>I have this, which works:</p>
  
  <pre><code>testLabel.text = [NSString stringWithFormat:@"%@ to %@", testLabel.text, newLabelText];
  </code></pre>
  
  <p>I wish I could use the "+=" operator, but I get a compile error (Invalid operands to binary +, have 'struct NSString *' and 'struct NSString *'):</p>
  
  <pre><code>testLabel.text += [NSString stringWithFormat:@"to %@", newLabelText];
  </code></pre>
  
  <p>Why can't I do this?  </p>
  
  <p>Also, how can I shorten my first snippet of code?</p>