问我的单元没有出现在我的tableView中

EN

import UIKit

class MyTableViewCell: UITableViewCell {

    @IBOutlet weak var labelHole: UILabel!

    @IBOutlet weak var labelShots: UILabel!
}

class SecondViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {

    @IBOutlet weak var holesTableView: UITableView!


    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return mainShotsEachHole.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        let cell = holesTableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! MyTableViewCell

        cell.labelHole?.text = "Hole \(mainCurrentHoleNumber)"

        cell.labelShots?.text = "\(mainShotsEachHole[indexPath.row])"

        return cell
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        holesTableView.register(MyTableViewCell.self, forCellReuseIdentifier: "cell")

        holesTableView.delegate = self
        holesTableView.dataSource = self
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}

import UIKit

var mainCounterValue = 0
var mainCurrentHoleNumber = 1
var mainShotsEachHole = [Int]()


class ViewController: UIViewController {

    @IBAction func unwindToViewController (segue: UIStoryboardSegue){

    }

    @IBOutlet weak var mainCounter: UILabel!

    @IBOutlet weak var mainHoleNumber: UILabel!

    @IBAction func mainButtonNextHole(_ sender: Any) {
        mainShotsEachHole.append(mainCounterValue)
        mainCurrentHoleNumber += 1
        mainHoleNumber.text = "Hole \(mainCurrentHoleNumber)"
        mainCounterValue = 0
        mainCounter.text = "\(mainCounterValue)"
    }


    @IBAction func mainButtonMinus(_ sender: Any) {
        if (mainCounterValue > 0) {
            mainCounterValue -= 1
        } else {
            mainCounterValue = 0
        }
        mainCounter.text = "\(mainCounterValue)"
    }

    @IBAction func mainButtonPlus(_ sender: Any) {
        mainCounterValue += 1
        mainCounter.text = "\(mainCounterValue)"
    }


    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}