Let's talk about Kotlin

This talk was originally given for Javabin and the Oslo Kotlin Meetup group on November 20th, 2019.

The code used in the presentation (along with more advanced examples) can be found at:
https://github.com/arnabkd/kotlin-javabin-demo

Transcript

1. KOTLIN LET’S TALK ABOUT
2. ABOUT ME As a teenager, Arnab dreamt of being a standup comedian, but somehow ended up finding the world of programming instead. He can be found coding away on his mac or dancing (sometimes both at the same time). Feel free to grab him and ask him any questions you want, especially about dogs.
3. KOTLIN WHY AM I SO IN LOVE WITH IT ▸ First and foremost: fi xes so many of the problems that Java suffered from ▸ Null safety built in the type safety ▸ Just…so many small utilities everywhere ▸ Functions are fi rst class citizens
4. INTRODUCTION
5. THE TYPE SYSTEM
6. DATA CLASSES
7. EXTENSION FUNCTIONS (ADD FUNCTIONALITY TO EXISTING CLASSES)
8. ▸ let, run, with, apply, also ▸ Key differences ▸ how they are called ▸ what the context object is called (this vs it) ▸ the return value ▸ Useful for throwaway contextual computations ▸ Read more here SCOPE FUNCTION
9. ▸ Uses “it” as the receiver argument ▸ Returns the last value computed in the lambda ▸ Useful for: conversions from type A to type B LET
10. ▸ Uses “this” as the receiver argument ▸ Returns the last value computed in the lambda ▸ Extremely similar to let ▸ Useful for: when you have side-effects. RUN
11. ▸ Uses “it” as the receiver argument ▸ Returns Unit (regardless of what is computed last) ▸ Useful for: adding log statements after a function returns ALSO
12. INTERMEDIATE
13. SEALED CLASSES
14. CHECK/REQUIRE
15. TYPEALIASES
16. INTERFACES BY DELEGATION
17. ADVANCED
18. LAZY
19. VETOABLE
20. OBSERVABLE
21. PARTIAL RETURNS
22. FUNCTIONAL COMPOSITIONS (HIGHER ORDER FUNCTIONS)
23. CONTACT INFO AND CODE ▸ Code from the presentation (and a bit more) can be found at https:// github.com/arnabkd/kotlin-javabin-demo ▸ Contact me at arnabkum@gmail.com or tweet me @arnab_travels
24. THANK YOU!