UILabel Text Code - swift

Question

I am new to programming. Really new and am trying to get the "outputLabel" to fade in when I press the "quoteButtonTapped" button. I have tried to set the alpha to 0.0 and then with a delay to alpha 1.0 but
self.outputLabel.alpha does not work.
Wow! I am perhaps missing something really basic here but the "quoteButtonTapped" does select a random quotation from an array and it's reference label, but how can I get the label text to fade in?
I included code below:
class ViewController: UIViewController {
#IBOutlet weak var outputLabel: UILabel!
#IBOutlet weak var borderImage: UIImageView!
#IBOutlet weak var scrollViewWindow: UIScrollView!
#IBOutlet weak var referenceLabel: UILabel!
#IBAction func quoteButtonTapped(sender: AnyObject) {
scrollViewWindow.contentSize.height = 800
}
override func viewDidLoad() {
super.viewDidLoad()
}
func displayCurrentScripture() {
let range: UInt32 = UInt32(quotes.count)
let randomNumber = Int(arc4random_uniform(range))
let QuoteString = quotes.objectAtIndex(randomNumber)
let ReferenceString = references.objectAtIndex(randomNumber)
self.outputLabel.text = QuoteString as? String
self.referenceLabel.text = ReferenceString as? String
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
UILabel.referenceLabel..
}
displayCurrentScripture()
}

Answer 1

Try This :
override func viewDidLoad() {
super.viewDidLoad()
displayCurrentScripture();
}
func displayCurrentScripture() {
let range: UInt32 = UInt32(quotes.count)
let randomNumber = Int(arc4random_uniform(range))
let QuoteString = quotes.objectAtIndex(randomNumber)
let ReferenceString = references.objectAtIndex(randomNumber)
self.outputLabel.alpha = 0.0
self.referenceLabel.alpha = 0.0
self.outputLabel.text = QuoteString as? String
self.referenceLabel.text = ReferenceString as? String
UIView.animateWithDuration(0.2, animations: { () -> Void in
self.outputLabel.alpha = 1.0
self.referenceLabel.alpha = 1.0
});
}