CountViewController.swift

class CountViewController: UIViewController {

    private let countLabel = UILabel()

    var count = 0 {
        didSet {
            countLabel.text = "Current count: \(count)"
        }
    }

    init() {
        super.init(nibName: nil, bundle: nil)
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func viewDidLoad() {
        count = 0

        view.addSubview(countLabel)

        // add contrainsts for positioning ...
    }
}