comparing local images swift - swift

Question

"Optional type Bool cannot be used as a boolean; test for !nil instead"
Is the error I'm getting
I'm trying to make a "slot machine" app, very basic,
You press the UIButton, and the three images should all change, randomly, if the 3 matches, print "You won!"
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var img1: UIImageView!
#IBOutlet weak var img2: UIImageView!
#IBOutlet weak var img3: UIImageView!
#IBOutlet weak var rollBtn: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func onRollPress(sender: AnyObject) {
let randomRoll = ImgArray().getRandomImage()
img1.image = randomRoll
img2.image = randomRoll
img3.image = randomRoll
if (img1.image! == img2 && img3) {
print("You won!")
}
}
}

Answer 1

If your images are in an array, why not get the indexes of the images and compare that. Or you could convert the images to base64 strings and compare those.
Edit: Not knowing much about your ImgArray class, this may work for you:
#IBAction func onRollPress(sender: AnyObject) {
let randomRoll1 = ImgArray().getRandomImage()
let randomRoll2 = ImgArray().getRandomImage()
let randomRoll3 = ImgArray().getRandomImage()
img1.image = randomRoll1
img2.image = randomRoll2
img3.image = randomRoll3
let imgIndex1 = ImgArray().indexOf(randomRoll1)
let imgIndex2 = ImgArray().indexOf(randomRoll2)
let imgIndex3 = ImgArray().indexOf(randomRoll3)
if (imgIndex1 == imgIndex2 && imgIndex3) {
print("You won!")
}
}