Uitextfield notificaton xcode 12

Question

how do uitextfield appear message must be filled first before it can be executed? I've searched Google but can't find it.

my design

Answer 1

Do you mean display a message saying that the textFields must be filled before advancing? If so, use an if statement on each textField

if namaField.text == "" || alamatField.text == "" || phoneField.text == "" {
    let alertController = UIALertController(title: "Enter all fields", preferredStyle: .alert)
    let okayAction = UIAlertAction(title: "Okay", style: .default, handler: { action in
        self.dismiss(animated: true, completion: nil)
    })
    alert.addAction(okayAction)
    self.present(alert, animated: true)
}