How to use Navigation Controller?

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I have this app with UIKit.

What I want to do is that when the Start Animal Quiz button is pressed in the question view controller, animal questions are displayed. If Start Soccer Quiz is pressed, soccer questions are shown in the question view controller.

First add a variable to your QuestionViewController that tracks the kind of quiz it is. You could use an enum for this like so

enum QuizType {
    case animals, football, undefined
}

var quizType: QuizType = .undefined

Now, you can use the prepareForSegue:sender: method to set this variable and then detect it in the QuestionViewController as shown below.

You would need to implement this method in both the view controllers that trigger the segue to the navigation controller.

In the view controller that has the ‘Start Animal Quiz’ button, you can define the method as below:

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if let navigationVC = segue.destination as? UINavigationController,
       let questionVC = navigationVC.viewControllers.first as? QuestionViewController {
        questionVC.quizType = .animals
    }
}

And in the view controller that has the ‘Start Futbol Quiz’ button, you can define the method as below:

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if let navigationVC = segue.destination as? UINavigationController,
       let questionVC = navigationVC.viewControllers.first as? QuestionViewController {
        questionVC.quizType = .football
    }
}

Then in your QuestionViewController, inside the viewDidLoad() method (or anywhere else you need), you'll be able to detect the kind of quiz it is and then set the questions accordingly like below:

switch quizType {
    case .animals:
        print("this is an animals quiz, load animal questions")
                
    case .football:
        print("this is an football quiz, load football questions")
                
    default: 
        print("this should not happen; show an error message or use a default quiz type")
}