Setting a max int value (not character count) to a UITextField

Question

In Swift, is it possible to set a max INT value to a UITextField?

My use-case is I have 5 text fields that need to have a maximum int value. These values range from

Answer 1

You can check if the current value in the text field is less than the maximum integer value you've specified:

(You might want to change the keyboard type to .NumberPad at this point to let user type only numeric values.)

textField.keyboardType = .NumberPad

--

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
  let newText = NSString(string: textField.text!).stringByReplacingCharactersInRange(range, withString: string)
  if newText.isEmpty {
    return true
  }
  else if let intValue = Int(newText) where intValue <= self.maxValue {
    return true
  }
  return false
}

I created an example project for you. You can download and play around with it.

Answer 2

Here's an update for Swift 4 and later that ensure the value entered is an integer in the range 0 to 5000.

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    let newText = (textField.text! as NSString).replacingCharacters(in: range, with: string) as String
    if let num = Int(newText), num >= 0 && num <= 5000 {
        return true
    } else {
        return false
    }
}