title: Store [String] in NSUserDefaults
body: <p>I want to save a Swift Style String Array into NSUserDefaults, but acutally the "if" statement in the code says that returnValue is always nil.</p>
  
  <p>Later in the code (iOS 8) I want to use "food += ["spaghetti"] to add new entries.</p>
  
  <pre><code>var food : [String] {
      get {
          var returnValue : [String]? = NSUserDefaults.standardUserDefaults().objectForKey("food") as? [String]
          if returnValue == nil      //Check for first run of app
          {
              returnValue = ["muesli", "banana"]; //Default value
          }
          return returnValue!
      }
      set (newValue) {
          NSUserDefaults.standardUserDefaults().setObject(newValue, forKey: "food")
          NSUserDefaults.standardUserDefaults().synchronize()
      }
  }
  </code></pre>