How to convert Optional String to String
<pre><code>@IBOutlet var navBar: UINavigationBar!
@IBOutlet var menuButton: UIBarButtonItem!
@IBOutlet var topicNameLabel: UILabel!
var topicName:String!
override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
    menuButton.target = self.revealViewController()
    menuButton.action = Selector("revealToggle:")

    navBar.barTintColor = UIColor(red: 0, green: 0.4176, blue: 0.4608, alpha: 1)
    topicNameLabel.text = self.topicName

}
</code></pre>

<p>That's my code, I will pass a string to the topicName by prepareForSegue, however, I find that in the simulator, my topicNameLabel shows "Optional(The text I want)". I just want the "The text I want", but do not need the Optional. Could any one help me?</p>