I noticed my images weren't visible, so: My storyboard: Simulator:

Do you mean like this? class ValidCardsCollectionViewController: UICollectionViewController { let dataSource: [String] = ["hearts", "clubs", "diamonds", "spades"] override func viewDidLoad() { super.viewDidLoad() print(dataSource) collectionView.dataSource = self collectionView.delegate = self } I tried doing this before but it doesn't seem to fix the problem.