Thread 1: Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional valueを解決したい

問題点

buttonを押すと次の画面に遷移するときに

Thread 1: Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value

というエラーメッセージがコンソールに出ました。
エラーの対象メソッドは以下の太文字の通りです
** picker2.delegate = self**

コードの概要

swift
1import UIKit
2
3class ResultViewController: UIViewController,UIPickerViewDelegate,UIPickerViewDataSource {
4    
5    @IBOutlet weak var mylabel2: UILabel!
6    
7    @IBOutlet weak var picker2: UIPickerView!
8    
9    let array2: [String] = ["hoge1","hoge2","hoge3","hoge4","hoge5"]
10    
11    override func viewDidLoad() {
12        super.viewDidLoad()
13        picker2.delegate = self
14               picker2.dataSource = self
15        // Do any additional setup after loading the view.
16    }
17    func numberOfComponents(in pickerView: UIPickerView) -> Int {
18        return 1 }
19    
20    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
21    return array2.count
22    }
23    
24    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
25        return array2[row]
26    }
27    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
28           self.mylabel2.text = String(array2[row])
29          
30       }