Swift - Add Navigation Bar title and buttons programmatically

See: https://www.hackingwithswift.com/example-code/uikit/how-to-add-a-bar-button-to-a-navigation-bar

If you build a stack of view controllers with a navigation controller, but without embedding a VC in the NC then you have to add the navigation bar and buttons programmatically to every VC.

01. Example with a title, left and right button

override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        self.navigationItem.title = "Profile Settings"
        self.navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(addTapped))
        self.navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Add", style: .plain, target: self, action: #selector(addTapped))
    }
    
    @objc func addTapped() {
        //Do something if the bar buttons are tapped
    }
    
02. Example with a title and two buttons on the right:

override func viewDidLoad() {
        super.viewDidLoad()
        self.navigationItem.title = "Third VC"
        let add = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(addTapped))
        let play = UIBarButtonItem(title: "Play", style: .plain, target: self, action: #selector(addTapped))
        self.navigationItem.rightBarButtonItems = [add, play]

    }
    
    
    @objc func addTapped() {
        //Do something if the bar buttons are tapped
    }