SEGUE
1. ViewController
 // In a storyboard-based application, you will often want to do a little preparation before navigation
  override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    
  // hier fehlt Code    
}

2/3./4. ViewController, für alle @IBAction override func unwind(for unwindSegue: UIStoryboardSegue, towards subsequentVC: UIViewController) { // hier fehlt kein Quellcode }

SaveData:NSUserDefaults
UITableView-Methoden