Saving the tableview text after edited swift

Question

I have managed to create a tableview with an array or messages and when i tapped a tableview cell it shows an alertview and a uitextfield that you can change the text of the tableview. What i'm trying to do now is to save the tableview text ("message") when it changed. Because when I go to another view controller and go back it does not save. I am new on swift programming and wondering how can i achieve that. I have read some articles that i need to use nsuserdefaults but i am not familiar with that. here is my code below. Thanks guys.

class Messages: UITableViewController {

    @IBOutlet var uitableView: UITableView!

    var tField: UITextField!
    var index: Int?
    var msgArray: [String]!

    var messages = ["Message 1", "Message 2", "Message 3", "Message 4", "Message 5", "Message 6"]

    override func viewDidLoad() {
        super.viewDidLoad()

        tableView.delegate = self
        tableView.dataSource = self

    }

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

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

        let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
        let messagesCell = messages[indexPath.row]
        cell.textLabel?.text = messagesCell

        return cell

    }

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

        let path = tableView.indexPathForSelectedRow
        index = path?.row

        changeMessage()
    }

    func changeMessage() {

        let alert = UIAlertController(title: "Message", message: "Enter new preset message", preferredStyle: UIAlertControllerStyle.alert)

        alert.addTextField(configurationHandler: configurationTextField)

        let doneAction = UIAlertAction(title: "Done", style: UIAlertActionStyle.default, handler:{ (UIAlertAction) in

            let modelString = self.tField.text
            self.messages[self.index!] = modelString!
            self.tableView.reloadData()

        })

        let cancelAction = UIAlertAction(title: "Cancel", style: .cancel, handler: nil)

        alert.addAction(doneAction)
        alert.addAction(cancelAction)
        self.present(alert, animated: true, completion: nil)
    }

    func configurationTextField(textField: UITextField!){
        if (textField) != nil {
            tField = textField
            textField.text = messages[index!]
        }
    }
}

Answer 1

Try to use nsuserdefaults. In SWIFT 3

override func viewWillAppear(_ animated: Bool) {

     //Get the array
     if let array = UserDefaults.standard.object(forKey:"messages") as? Array<String> {

           self.messages = array
     }

}


func changeMessage() {

    let alert = UIAlertController(title: "Message", message: "Enter new preset message", preferredStyle: UIAlertControllerStyle.alert)

    alert.addTextField(configurationHandler: configurationTextField)

    let doneAction = UIAlertAction(title: "Done", style: UIAlertActionStyle.default, handler:{ (UIAlertAction) in

        let modelString = self.tField.text
        self.messages[self.index!] = modelString!
        UserDefaults.standard.set(self.messages, forKey: "messages") // Set the array with changes
        self.tableView.reloadData()

    })

    let cancelAction = UIAlertAction(title: "Cancel", style: .cancel, handler: nil)

    alert.addAction(doneAction)
    alert.addAction(cancelAction)
    self.present(alert, animated: true, completion: nil)
}

Answer 2

        let defaults = UserDefaults.standard
        defaults.set("123", forKey: "oldString")
    print("\(UserDefaults.standard.value(forKey: "oldString")!)")

This may help you.