extension CreateNotViewController: UITextFieldDelegate {
    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        let maxLength = 15
        let currenString: NSString = textField.text! as NSString
        let newString: NSString = currenString.replacingCharacters(in: range, with: string) as NSString

        return newString.length <= maxLength
    }
}

override func viewDidLoad() {
        super.viewDidLoad()
        notifTitle.delegate = self
        ...
    }