How to restrict character input in UITextfield?

Question

Objective-C

I give the dictionary application and I need to prohibit entering the text field of the word in Russian!
How can I do that?

Answer 1

UITextField provides a wonderful delegate method - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string - which is great for validating input. And for the check itself, it’s more convenient for me to use the regular expression - stackoverflow.com/questions/15392031/uitextfield-t...

Answer 2

https://vk.com/videos-58860049?section=all&z=video...