title: How to get current language code with Swift?
body: <p>I want get the language code of the device (en, es...) in my app written with Swift. How can get this?</p>
  
  <p>I'm trying this:</p>
  
  <pre><code>var preferredLanguages : NSLocale!
  let pre = preferredLanguages.displayNameForKey(NSLocaleIdentifier, value: preferredLanguages)
  </code></pre>
  
  <p>But this returns nil.</p>