title: How to set image for button in Swift/Xcode
body: <p>I am receiving a "nil" error when trying to set the image for a button programmatically. What am I doing wrong? These are all not optionals. </p>
  
  <pre><code>@IBOutlet weak var scrollView: UIScrollView!
  
  var imageButton: UIButton!
  var index: Int = 0
  
  var images: [UIImage] = [UIImage(named: "image1.png")!, UIImage(named: "image2.png")!, UIImage(named: "image3.png")!, UIImage(named: "image4.png")!, UIImage(named: "image5.png")!, UIImage(named: "image6.png")!, UIImage(named: "image7.png")!, UIImage(named: "image8.png")!, UIImage(named: "image9.png")!, UIImage(named: "image10.png")!, UIImage(named: "image11.png")!, UIImage(named: "image12.png")!, UIImage(named: "image13.png")!, UIImage(named: "image14.png")!, UIImage(named: "image15.png")!, UIImage(named: "image16.png")!, UIImage(named: "image17.png")!, UIImage(named: "image18.png")!, UIImage(named: "image19.png")!, UIImage(named: "image20.png")!, UIImage(named: "image21.png")!, UIImage(named: "image22.png")!, UIImage(named: "image23.png")!, UIImage(named: "image24.png")!, UIImage(named: "image25.png")!, UIImage(named: "image26.png")!, UIImage(named: "image27.png")!, UIImage(named: "image28.png")!, UIImage(named: "image29.png")!, UIImage(named: "image30.png")!]
  
  
  override func viewDidLoad() {
      super.viewDidLoad()
      // Do any additional setup after loading the view, typically from a nib.
  
      let screenSize: CGRect = UIScreen.mainScreen().bounds
      let screenWidth = screenSize.width
      //let screenHeight = screenSize.height
  
      let numWidth: CGFloat = 3
      let numHeight: CGFloat = 10
      self.scrollView.frame.size.width = screenWidth
      let width: CGFloat = (self.scrollView.frame.size.width - (numWidth + 1))/3
  
      for var i:CGFloat = 0; i &lt; 3; ++i{
          for var j:CGFloat = 0; j &lt; 10; ++j {
  
              let image: UIImage = images[index] as UIImage!
  
  
              imageButton.setImage(image,forState:UIControlState.Normal)
              imageButton.frame = CGRectMake(width*i, width*j, width, width)
              self.scrollView.addSubview(imageButton)
  
              index++
          }
      }
      scrollView.contentSize.height = (width)*numHeight
  </code></pre>