Swift prevent "0" being first character for 1 specific uiTextField - ios

Question

so i search online about how "func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool" for formating textField. i found this way to prevent "0" as my first char in my textfield. it works but, actually not the way i wanted.
The thing is, in my register view theres 4 uiTextfield, which contain :
Name
Phone Number
Pin
Confirm Pin
i only want to prevent "0" as my first char only for my PhoneNum TextField. but with this code, i kinda put all of those 4 textField into prevent "0" as the first char.
here's my code :
#IBOutlet weak var textFullName: SkyFloatingLabelTextField!
#IBOutlet weak var textPhoneNumber: SkyFloatingLabelTextField!
#IBOutlet weak var textPIN: SkyFloatingLabelTextField!
#IBOutlet weak var textConfirmPIN: SkyFloatingLabelTextField!
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
// I try this one
if string == "0" {
if textField.text!.count == 0 {
return false
}
}
// i also try to change the "textField" into "textPhoneNumber"
if string == "0" {
if textPhoneNumber.text!.count == 0 {
return false
}
}
// both of those method wont work
return true
}
can someone tell me how to just prevent my textPhoneNumber to cannot type "0" as its first char? with this method i only put all of my textfield into cannot type "0" as its first char.
Thanks guys

Answer 1

The UITextFieldDelegate methods will get called for ALL of the text fields for which the view controller is set up as the delegate.
Presumably your textField(_:shouldChangeCharactersIn:replacementString:) method is being called for all 4 of your SkyFloatingLabelTextField objects (which I assume are a custom subclass of UITextField.)
If you want different behavior for different text fields, you need to write your code to handle each case separately. Something like this:
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
switch textField {
case textPhoneNumber:
//Special case code to handle the phone number field
if string == "0" {
if textField.text!.count == 0 {
return false
}
return true
}
case textFullName:
//Special case code to handle the name field (if needed.)
default:
//Shared code to handle the other fields the same way
}
}

Answer 2

You can check if the textField is textPhoneNumber directly by using the equatability == sign.
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
if textField == textPhoneNumber {
// do textPhoneNumber stuff
} else {
// others
}
return true
}