title: how to update a label when user is typing into a textview?
body: <p>Hey I'm new to Swift and having some problems with my code.</p>
  
  <p>Suppose I have two objects:</p>
  
  <pre><code>IBOutlet var textView: NSTextView!
  IBOutlet weak var label: NSTextField!
  </code></pre>
  
  <p>So I want "label" to displays the current number of characters that is in the  textView.</p>
  
  <p>But I'm not sure how to make the "label" update automatically whenever the text in the textView changes (when user types in/ deletes)?</p>
  
  <p>Can anyone help me ?</p>
  
  <p>Thanks</p>