字符串不通过segue？

Question

I'm trying to build a cell that can be tapped, store the current text of the cell label, and send that label to a different view controller. I've looked everywhere and can't figure out why it's not passing

View controller with table view

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "openWave" {
        if let destVC = segue.destination as? GoToWaveViewController {
            destVC.waveLabel = sender as! String
            print("sdf: \(sender)")
        }
    }
} ...

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    let cell = self.tableView.cellForRow(at: indexPath) as! MyWavesTableViewCell
    let text = cell.waveLabel.text!
    let label = self.groupNames[indexPath.row]
    print(label)
    performSegue(withIdentifier: "openWave", sender: label)
    //self.tableView.deselectRow(at: indexPath, animated: true)}

Second View Controller

class GoToWaveViewController: UIViewController {

@IBOutlet weak var waveName: UILabel!
var waveLabel: String!

override func viewDidLoad() {
    super.viewDidLoad()

}

override func viewWillAppear(_ animated: Bool) {
    setProperties()
}

func setProperties() {
    self.waveLabel = self.waveName.text!
    print("asdf: \(waveLabel)")
    print("asdfa: \(self.waveLabel)")
}

Answer 1

I see it's a logical error you may need

self.waveName.text =  self.waveLabel

Instead of

self.waveLabel = self.waveName.text!

And that overwrites the sended value , so this

print("asdf: \(waveLabel)")
print("asdfa: \(self.waveLabel)")

will print empty values

Answer 2

Well, when your view appears, you call setProperties , which overwrites self.waveLabel with the text from self.waveName . This line

self.waveLabel = self.waveName.text!

should be replaced with

self.waveName.text = self.waveLabel

Secondarily, fix your names! Label is a bad name for something that is a string . If I were looking at this code, it's immediately think that waveName is a string and waveLabel is the label, but that is the opposite of what you have here.