Chapter 4 - Bronze Challenge

gistfile1.txt

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
    
    let existingTextHasDecimalSeparator = textField.text?.rangeOfString(".")
    let replacementTextHasDecimalSeparator = string.rangeOfString(".")
    
    let decimals = NSCharacterSet.decimalDigitCharacterSet()
    
    if string.lowercaseString.rangeOfCharacterFromSet(decimals) == nil && string != "." && string.characters.count >= 1 {
        return false
    } else {
        if existingTextHasDecimalSeparator != nil && replacementTextHasDecimalSeparator != nil {
            return false
        } else {
            return true
        }
    }
}

@dpauk, nice solution!!!!