Kotlin - What, Why, Where and How?

Introduction to Kotlin at Kotlin usergroup meetup #3

Transcript

1. What, Why, Where and How? Marko Arsić Belgrade, April 2017
2. Introduction
3. Marko Arsić A polyglot developer deeply interested in high performance, software architecture and generally solving complex problems. Typing code since 2010 Mobile Team Lead at
4. Topics • What is Kotlin? • Why Kotlin? • How to use it? • Demo • Where to start? • Flaws • Summary • Kotlin UG
5. What is Kotlin?
6. New kid in the code town “Statically typed Programming Language targeting JVM and JavaScript.” Sponsored and Developed by Language for JVM, Android and the browser!
7. … compiles to JVM bytecode or JavaScript. … comes from industry, not academia … solves problems faced by working programmers … programs can use all existing Java fw and libraries … imposes no runtime overhead … standard library is small and tight … IDE interop is entirely seamless
8. CURRENT STATE 1.0 Release was on 15th February 2016 20+ Developers at JetBrains 100+ Committers Used in close to 10 Products at JetBrains
10. First Technology Preview of Kotlin/Native Kotlin/Native is another step toward making Kotlin usable throughout a modern application. The Kotlin/Native compiler produces standalone executables that can run without any virtual machine.
12. Why do you need to try use Kotlin?
13. – Danny Preussler “Kotlin stole got inspired by the best from of the best”
14. – Martin Odersky (Lead designer of Scala) “Kotlin is a nice language that got a few ideas from Scala. It's a less ambitious version of Scala.”
15. Exactly what we needed Concise - Reduce the amount of boilerplate code Safe - Avoid errors such as null pointer exceptions. Versatile - Build all in same language Interoperable -100% Java Interoperability
16. And more • Lean syntax type inference works everywhere • Real properties generate getFoo/setFoo methods behind the scenes for Java interop. • Functions can exist outside of classes. • Exceptions are unchecked. • Functional programming support with lambdas and ability to do mapping, folding etc over standard Java collections • Extension functions let you add methods to classes without modifying their source code. • Function arguments can be named, optional and variadic.
17. “If something annoyed you about Java, there is 50/50 chance that it’s fixed in Kotlin"
18. How to use it?
19. As you wish Command Line Maven 
 Gradle Ant 
 IntelliJ IDEA Android Studio NetBeans Eclipse
20. LET’S SEE SOME CODE
21. Where to start using it?
22. Production ready • Start small • Domain classes • Util classes • Tests • Automatic conversion of Java to Kotlin • Embrace functional approach
23. Flaws
24. “There are three simple realities: nothing lasts, nothings is finished and nothing is perfect.”
25. SUMMARY • Pragmatic Language • Easy Learning Curve • Interoperability provides low risk/high reward upgrade • Modern and Enjoyable • Kotlin is here to stay
26. User Group Serbia Kotlin as modern programming language One meetup each month @kotlin_serbia meetup.com/Serbia-Kotlin-User-Group facebook.com/kotlinserbia
27. THANK YOU @mArsic | marsic.info