How pass data from one ViewController to another one Xcode?

Question

So i have a quiz and when the quiz ends i want to show how many answers were correct. Here is how i have tryed to do it.

This is the first VC

import UIKit

class QuizViewController: UIViewController {



@IBOutlet weak var timer: UILabel!
@IBOutlet weak var question: UILabel!
@IBOutlet weak var image: UIImageView!
@IBOutlet weak var prasanje: UILabel!

//odgovori

@IBOutlet weak var odgovor1: UIButton!
@IBOutlet weak var odgovor2: UIButton!
@IBOutlet weak var odgovor3: UIButton!

let allQuestions = QuestionBank()
let randomQuestions = QuestionBank.shared.getRandomQuestions(6)
var questionNumber: Int = 0
var score: Int = 0
var selectedAnswer: Int = 0
let updateT = EndViewController()

var taimer:Timer?
var seconds: Int = 60

override func viewDidLoad() {
    super.viewDidLoad()

    updateQuestion()
    updateUI()

}

@IBAction func Back(_ sender: Any) {
     let dialogMessage = UIAlertController(title: "Потврдете", message: "Дали сте сигурни дека сакате да прекинете?", preferredStyle: .alert)

    let ok = UIAlertAction(title: "Да", style: .default, handler: { (action) -> Void in
                print("Ok button tapped")
        self.dimiss()
           })

    let cancel = UIAlertAction(title: "Откажи", style: .cancel) { (action) -> Void in
               print("Cancel button tapped")
           }

    dialogMessage.addAction(ok)
    dialogMessage.addAction(cancel)

    self.present(dialogMessage, animated: true, completion: nil)
}

func dimiss(){
    self.dismiss(animated: true, completion: nil)
}

@IBAction func odgovorpotvrden(_ sender: UIButton) {
    if sender.tag == selectedAnswer {
        print("correct")
        score += 1
    }else {
        print("wrong")
    }
    questionNumber += 1
    updateQuestion()
}

func updateQuestion() {

    if questionNumber <= randomQuestions.count - 1{
    image.image = UIImage(named:(randomQuestions[questionNumber].image))
    prasanje.text = randomQuestions[questionNumber].prasanje
    odgovor1.setTitle(randomQuestions[questionNumber].odgovor1, for: UIControl.State.normal)
    odgovor2.setTitle(randomQuestions[questionNumber].odgovor2, for: UIControl.State.normal)
    odgovor3.setTitle(randomQuestions[questionNumber].odgovor3, for: UIControl.State.normal)
    selectedAnswer = randomQuestions[questionNumber].tocenodgovor
    }
    else {
        endVC()
    }
    updateUI()


}

func updateUI() {
    question.text = "\(questionNumber)/\(randomQuestions.count)"

    let min = (seconds / 60) % 60
    let sec = seconds % 60

    timer!.text = String(format: "%02d", min) + ":" + String(format: "%02d", sec)

    time()
}

func time() {

    if taimer == nil {
        taimer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { timer in
            if self.seconds == 0{
                self.timeup()
            }else if self.seconds <= 60 {
                self.seconds -= 1
                self.updateUI()
            }
        }
    }

}

func timeup() {
    taimer?.invalidate()
    taimer = nil

   let timeup = UIAlertController(title: "Времето истече", message: "Крај на испитот. Дали сакате да започнете од почеток?", preferredStyle: .alert)
    let restart = UIAlertAction(title: "Ресетирај", style: .default, handler: { (action) -> Void in
                print("restart button tapped")
                    self.restartQuiz()})

    let dismiss = UIAlertAction(title: "Откажи", style: .default, handler: { (action) -> Void in
                    print("dismiss button tapped")
                        self.dimiss()})
    timeup.addAction(restart)
    timeup.addAction(dismiss)

    self.present(timeup, animated: true, completion: nil)
}
func updateScore(){
    if score > randomQuestions.count - 2 {
        updateT.no1 = "Cestitki"

    }else {
        updateT.no1 = "uaa"

    }

}

func restartQuiz() {
    seconds = 60
    score = 0
    questionNumber = 0
    updateQuestion()

}

@IBAction func endVC() {
      let sb = UIStoryboard(name: "Main", bundle: nil)

      if let endVC    = sb.instantiateViewController(identifier: "endVC") as? EndViewController{
          self.present(endVC, animated: true, completion: nil)

      }
}

And here is the VC that im trying to pass the data to.

import UIKit

class EndViewController: UIViewController {




@IBOutlet weak var cestitki: UILabel!
@IBOutlet weak var skor: UILabel!

var no1: String = ""
var no2: String = ""

override func viewDidLoad() {
    super.viewDidLoad()

    cestitki!.text = no1


}

But when i run the program the label is blank and there is nothing.

Im either trying to pass the "score" value form one to the other VC or change the label from the first VC in the second. Both helps

How you present VC that want to pass data ? What is `updateT` — Omer Tekbiyik, Jun 15 '20 at 14:58
where you are creating `updateT` and how you go to that controller either by segue or present or push ? — Jawad Ali, Jun 15 '20 at 15:08
"And here is the VC that im trying to pass the data to" When? I see a reference to an EndViewController, but I see no evidence that you ever "go" to that view controller. Merely saying `EndViewController()` does not refer to an _existing_ view controller, and it does not _navigate_ anywhere. — matt, Jun 15 '20 at 15:28

Frankenstein · Answer 1 · 2020-06-15T15:26:06.457

Here's what you need, just modify the endVC method to present the updateT instance of EndViewController you've just created and the data should show up:

@IBAction func endVC() {
    present(updateT, animated: true, completion: nil)
}

Note: This would work if the EndViewController layout is created programmatically. If it's done via storyboard then you need to modify the instance of updateT that you created using the empty initializer for EndViewController. If it's done via storyboard you need to do this:

class QuizViewController: UIViewController {
    //...
    var updateT: EndViewController!

    override func viewDidLoad() {
        super.viewDidLoad()
        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        updateT = storyboard.instantiateViewController(withIdentifier: "endVC") as? EndViewController
        //...
    }
    //...
    @IBAction func endVC() {
        present(updateT, animated: true)
    }
}

How pass data from one ViewController to another one Xcode?

1 Answers1