title: Swift's guard keyword
body: <p>Swift 2 introduced the <code>guard</code> keyword, which could be used to ensure that various data is configured ready to go. An example I saw on <a href="http://www.hackingwithswift.com/swift2">this website</a> demonstrates an submitTapped function:</p>
  
  <pre><code>func submitTapped() {
      guard username.text.characters.count &gt; 0 else {
          return
      }
  
      print("All good")
  }
  </code></pre>
  
  <p>I am wondering if using <code>guard</code> is any different than doing it the old fashioned way, using an <code>if</code> condition. Does it give benefits, which you could not get by using a simple check?</p>