UITextField Should accept number only values

Question

I have UITexfields i want that it should accept only number other shows alert that enter a numeric value. I want that motionSicknessTextFiled should only accept number

Answer 1

Here is the working example for swift 4

public func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool
{
    // Allow Backspace
    if string.count == 0 {
        return true
    }

    // Allow Only Valid Decimal Numbers
    if let textFieldText = textField.text   {

        let finalText = (textFieldText as NSString).replacingCharacters(in: range, with: string)
        if Double(finalText) != nil {
            return true
        }
    }
    return false
}