Regex differences between Kotlin and Swift

Issue

I have an application implemented in Android with Kotlin and in iOS with Swift.

I want the backend to send with a response to the clients a regular expression. This regular expression must then be checked in both apps in order to see if it matches a user's input.

Question: Do regular expressions have the same syntax in both Kotlin and Swift? If not, what are their differences?

Solution

For anyone who may have the same question, after some research, I came to the conclusion that Swift uses ICU for regular expressions, while Kotlin is using the regular expression syntax that Java uses and has this pattern syntax.

You can find the exact differences between ICU and Java regular expressions here.

Answered By - Thanasis M