Protocol Delegate Method is not called in Swift

Question

Protocol delegate method is not called..

First View controller code

class ViewController: UIViewController,customDelegate {

  var          


        

Answer 1

First View Controller

import UIKit

class ViewController: UIViewController, SecondVCDelegate {
    @IBOutlet weak var label: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if let secondVC = segue.destination as? SecondViewController {
            secondVC.delegate = self
        }
    }        

    func didSelectData(_ result: String) {
        label.text = result
        print(result)
    }
}

Second View Controller

import UIKit

protocol SecondVCDelegate: class {
    func didSelectData(_ result: String)
}

class SecondViewController: UIViewController {
    @IBOutlet weak var button: UIButton!

    weak var delegate: SecondVCDelegate?

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    @IBAction func buttonTapped(_ sender: UIButton) {
        delegate?.didSelectData("My result")
        dismiss(animated: true, completion: nil)
    }
}