Kotlin is officially endorsed by Google for Android development but what is all the fuss about? Why should accomplished Java developers care? Here I explore some of the history, fundamentals, and tools that Kotlin provides for Android developers.

1. Say Goodbye to Java: Getting
Started With Kotlin for
Android
Adam Magaña

2. Introduction

3. Introduction
● Adam Magaña
● Lead Mobile Engineer @ Drund
● Currently spending most of my development time working on our Android
application.

4. A Quick History of Kotlin

5. A Quick History of Kotlin
● Created by JetBrains
○ Creator of IntelliJ, the IDE that powers Android Studio
● First release - July 2011
● Latest release (1.1.3) - June 2017
● Official endorsement by Google as first-class language - May 2017
● 8,000+ total releases on GitHub

6. “We believe Kotlin is an excellent fit for
Android not only because it gives
developers what they want, but also
because it matches the spirit of
Android.”
- Google Developer Product Group

7. Companies Using Kotlin

8. Companies Using Kotlin
● Pinterest
● Netflix
● AWS
● Uber
● Square
● Trello

9. 10%
Reduction in total methods after converting Basecamp to Kotlin.

10. 30%
Reduction in total lines of code after converting Basecamp to Kotlin.

11. Addressing Common Concerns

12. “But I’m comfortable and experienced
with Java.”
● That’s great!
● You ultimately have to use what you’re most comfortable with.
● BUT “give it 5 minutes” before reacting.

13. “I don’t want to convert my entire
codebase to a new language.”
● Kotlin can be any percentage of your project.
● Fully compatible with JDK 6.
● 100% interoperable with existing Java code.

14. “I don’t need Kotlin’s special tools to get
the job done.”
● An experienced developer absolutely doesn’t need Kotlin.
● Much can be accomplished with Java.
● BUT barring architectural/performance issues, why would you want
to have less tools available to you?

15. “I’m worried about the performance
implications of using Kotlin.”
● Performance is as good as an equivalent Java application.
● Kotlin lambdas often run faster than the same code written in Java.
● Incremental project builds using Kotlin are usually faster.

16. A Very Small Soapbox

17. A Very Small Soapbox
● Don’t let anyone, myself included, make you feel inadequate for choosing a
different programming language or platform than them.
● Will there be better alternatives to what you use? Yes.
● Does that mean the service you provide to your users is sub-par? No.
● Is it okay to have differing opinions about certain technologies? Absolutely.
● Important to be supportive.

18. We’re all in this together.

19. Setting Up Kotlin in Android
Studio

20. Setting Up Kotlin in Android Studio
● Extremely easy setup for both major versions of AS
● Plugin for AS 2.3.X
○ Preferences > Plugins > Install JetBrains Plugin
● Baked-in support in AS 3.0.0 (beta)
○ Also includes:
■ A new profiler tool
■ A network/request analyzer (!)

21. Installing the plugin for AS 2.3.X

22. Kotlin: The Basics

23. Kotlin: The Basics - Variable Declarations

24. Kotlin: The Basics - Function Declarations

25. Kotlin: The Basics - Class Declarations

26. Kotlin: The Cool Parts

27. Kotlin: The Cool Parts - Data Classes (http://bit.ly/2xhvVlh)

28. Kotlin: The Cool Parts - Elvis Operator

29. Kotlin: The Cool Parts - Extension Functions

30. Kotlin: The Cool Parts - Named and Default Arguments

31. Kotlin: The Cool Parts - When

32. Kotlin: The Cool Parts - Operator Overloading

33. Kotlin: The Cool Parts - Object Desctructuring

34. Kotlin: The Cool Parts - Custom Infix Operators

35. Kotlin: The Cool Parts - And Much More!
● Lambda functions
● Easier string interpolation
● Simplified getter/setter syntax
● Coroutines
● “Synthetic” plugin to replace findViewById (similar to Butterknife)

36. Converting Java to Kotlin

37. Converting Java to Kotlin - Using the Converter

38. Converting Java to Kotlin - Double Bangs

39. Converting Java to Kotlin - Companion Objects

40. Drawbacks To Kotlin

41. Drawbacks To Kotlin
● It’s new
○ Initial development with Kotlin will be slower
○ Code patterns/anti-patterns not fully flushed out yet
● Java has more robust static analysis tools
● Much smaller developer community than Java’s
● Adds ~727kB to the total size of your project

42. Over time the benefits
of using Kotlin will
continue to grow.

43. Give it a try!

44. Thank you!
Twitter: @adammagana
GitHub: @adammagana