Create label and set layout programmatically.

gistfile1.txt

class ViewController: UIViewController {
    
    // MARK: - Properties
    
    let titleLabel: UILabel = {
        let textLabel = UILabel()
        textLabel.text = "Monday"
        textLabel.font = UIFont.boldSystemFont(ofSize: 34)
        textLabel.textAlignment = .center
        return textLabel
    }()
    
    // MARK: - Lifecycle
    
    override func loadView() {
        super.loadView()
        
        view.addSubview(titleLabel)
        
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        setupLyout()
        
    }
    
    // MARK: - Private functions
    
    private func setupLyout() {
        titleLabel.translatesAutoresizingMaskIntoConstraints = false
        titleLabel.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
        titleLabel.topAnchor.constraint(equalTo: view.topAnchor, constant: view.bounds.height * 0.1).isActive = true
        titleLabel.widthAnchor.constraint(equalToConstant: view.bounds.width).isActive = true
        titleLabel.heightAnchor.constraint(equalToConstant: view.bounds.height * 0.1).isActive = true
    }
    
}