title: titleLabel.text vs currentTitle in Swift
body: <p>I am trying to make a simple calculator with Swift. I want to get the "text" on the buttons I created. The instructor in the tutorial is using a property:</p>
  
  <pre><code>@IBAction func appendDigit(sender: UIButton) {
      let digit = sender.currentTitle
  }
  </code></pre>
  
  <p>The question is, if I did this:</p>
  
  <pre><code>@IBAction func appendDigit(sender: UIButton) {
      let digit = sender.titleLabel.text
  }
  </code></pre>
  
  <p>What's the difference? Will they yield the same results?
  If so, how does one know when to use which?</p>