How to check text field input at real time?

Question

I am writing validation for my textfield, I found something interesting that whether I can check how many digits I am typing into the textfield at real time. My text field i

Answer 1

Update Swift 4.0

 txtFieldAdd.addTarget(self, action: #selector(textFieldDidChange(_:)), for: .editingChanged)

Now call your function. In my case, this will enable the save button

@objc func textFieldDidChange(_ textField: UITextField) {
    if (txtFieldAdd.text?.isEmpty)! {
        btnSave.isEnabled = false
    }
    else {
        btnSave.isEnabled = true
    }
}

Hope it helps.