title: How to display an image using URL?
body: <p>The error is: 
      "fatal error: unexpectedly found nil while unwrapping an Optional value"</p>
  
  <p>I am doing the following in ViewController:</p>
  
  <pre><code>var imageURL:UIImageView!
  
  override func viewDidLoad() {
      super.viewDidLoad()
      let url = NSURL(string:"http://cdn.businessoffashion.com/site/uploads/2014/09/Karl-Lagerfeld-Self-Portrait-Courtesy.jpg")
      let data = NSData(contentsOfURL:url!)
      if data!= nil {
          imageURL.image = UIImage(data:data!)
      }
  }
  </code></pre>
  
  <p>I really don't understand why it will report an error on </p>
  
  <pre><code>imageURL.image = UIImage(data:data!)
  </code></pre>
  
  <p>while I already told it not to proceed if data is nil.
  It is not the problem of the link.
  Nor is there problem with the "data". I tried to print it and it was not nil.</p>