How to restrict UITextField to take only numbers in Swift?

Question

I want the user to only enter numeric values in a UITextField. On iPhone we can show the numeric keyboard, but on iPad the user can switch to any keyboard.

Answer 1

Here's an cleaner solution:

 guard CharacterSet(charactersIn: "123456789").isSuperset(of: CharacterSet(charactersIn: string)) else {
     return false
 }
 return true

For decimals just add ., example 123456789.