Kotlin Multiplatform

Given at an internal company knowledge sharing meeting.

This presentation is about the "basics" behind Kotlin Multiplatform.

Transcript

1. Kotlin Multiplatform
2. Kotlin Kotlin/JVM Kotlin/Native Kotlin/JS Kotlin Multiplatform Easter Egg
3. Kotlin Kotlin/JVM Kotlin/Native Kotlin/JS Kotlin Multiplatform Easter Egg
4. Warning: The next slides are not 100% accurate but give you a visualisation about how Kotlin Multiplatform works
5. Fact: Kotlin is a Programming language.
6. Fact: Each language has to converted to something which can be understand by "a computer". We call these converters compiler.
7. Fact: Jetbrains provides different compilers for one language.
8. Fact: Jetbrains provides different compilers for one language. 1. JVM 2. Native 3. JS
9. Fact: Kotlin can be converted to Java Bytecode (via JVM compiler) Machine code (via Native compiler) JavaScript (via JS compiler)
10. fun main() { println("HelloWorld") } Example $ kotlinc HelloWorld.kt -include-runtime -d hello.jar $ java -jar hello.jar HelloWorld $ konanc HelloWorld.kt -o hello $ ./hello.kexe HelloWorld $ kotlinc-js HelloWorld.kt -output hello.js $ cat hello.js // JS Code nobody wants to see
11. Please note that we talk about pure Kotlin code. No dependencies to other worlds (like JVM, C or JS).
12. But - because the compiler knows about other worlds it is possible to use the respective dependencies!
13. Example expect currentTime: Long fun printTime() { println("It is $currentTime o'clock") } common.kt // No dependencies to other worlds actual currentTime: Long = java.lang.System.currentTimeMillis() fun main() = printTime() jvm.kt actual currentTime: Long = platform.posix.time(null) fun main() = printTime() native.kt actual currentTime: Long = kotlin.js.Date.now() fun main() = printTime() js.kt
14. Now we can compile each target (jvm, native, js) with the respective compiler
15. Questions so far?