Read value from TextField and convert to Int

@IBAction func raiseNumber(_ sender: Any) {
    guard let text = numbeRaisingTextField.text, let number = Int(text) else {
        showAlertButtonTapped(title: "Bad enter!", message: "Enter integer value!")
        return
    }

    let result = number * number
    numberRaisingLabel.text = "\(result)"
    numbeRaisingTextField.text! = ""
}