Conclusion

When used correctly, Kotlin extension functions can positively impact your project. They make your code significantly cleaner and ensure critical business logic, like regulatory logic, can remain in a central, easy-to-debug location. Just make sure that you don’t overuse them and that you understand the potential interoperability risks.

The key is to use these functions for your app’s critical business logic or utility functions that make no sense to exist in a separate class. For example, a function that takes a collection and grabs the third item or null if it doesn’t exist is a good case for Kotlin extension functions. Feel free to experiment and design, but know that Kotlin extension functions have the power to make your development easier.