ios - How to allow only certain set of numbers in a UITextfield in swift 2.0

Question

I am having a UITextField in which i get the month number as input. I am successful in limiting the no of characters to 2 in the UITextField. But i want users to enter only the values from 1 to 12 and none other than that. This has to be done simultaneously when the user types the numbers i.e in func textField(textField: UITextField!, shouldChangeCharactersInRange range: NSRange, replacementString string: String!) -> Bool. If i use a simple if condition to check the each character and return false in else part the textfield won't allow me to use clear or retype any other character. someone help me.

Answer 1

Set keyboard type as Number Pad

add this

func textField(textField: UITextField!, shouldChangeCharactersInRange range: NSRange, replacementString string: String!) -> Bool {

    if let text = textField.text {

        let newStr = (text as NSString)
            .stringByReplacingCharactersInRange(range, withString: string)
        if newStr.isEmpty {
            return true
        }
        let intvalue = Int(newStr)
        return (intvalue >= 0 && intvalue <= 12)
    }
    return true
}