(Swift) PrepareForSegue: fatal error: unexpectedly found nil while unwrapping an Optional value

Question

DetailViewController:

    @IBOutlet var selectedBundesland: UILabel!

TableViewController:

    override func prepareForSegue         


        

Answer 1

DetailViewController:

var textValue: String = ""
@IBOutlet weak var selectedBundesland: UILabel!

override func viewDidLoad() {
    super.viewDidLoad()
    selectedBundesland.text = textValue
}

TableViewController:

     if (segue.identifier == "BackToCalculator") {  
         var vc:FirstViewController = segue.destinationViewController as FirstViewController
         vc.textValue = "Test"
}