I m curious why does Kotlin create a class implementation in

Question

I m curious why does Kotlin create a class implementation instead of default methods when creating an interface with methods that have a body I now you can change that

Tim Oltjenbruns · Answer

probably so it can support earlier versions of Java that don t have default methods

Joffrey · Answer

It was not possible to do so with bytecode lt JVM 8 so they had to do it another way When compiling to bytecode 8+ you can now choose to use default methods it might even be the default now ~ remember the initial target was Android ~

Jan · Answer

Ah okay thanks

ephemient · Answer

Android was not the initial target I don t know why people think that

Casey Brooks · Answer

gt remember the initial target was Android Not exactly Kotlin existed for like 7 years before Google adopted it for Android Jetbrains created it initially for their own use which at the time was on Java 6 Kotlin has always been a much bigger thing than just Android

ephemient · Answer

<https wiki jvmlangsummit com index php title=Kotlin|https wiki jvmlangsummit com index php title=Kotlin> first public announcement

ephemient · Answer

<https blog jetbrains com kotlin 2011 07 hello world 2 |https blog jetbrains com kotlin 2011 07 hello world 2 > a bit of a retrospective around the time of 1 0 gt Ten years of Java development led us to feeling that our productivity at JetBrains could be improved significantly by using a modern JVM language alongside Java

ephemient · Answer

exactly the connection with Android only came as the community started using it later with Google picking it up after that

Joffrey · Answer

Fair enough that was not quite correct They did have to maintain compat with JDK lt 8 even until recently because of Android though while the rest could more easily upgrade to more recent JDKs

Jan · Answer

Do you need another compiler argument when using the compiler option Xjvm default=all Because I get a Inheritance from an interface with JvmDefault error

gildor · Answer

because of Android though while the rest could more easily upgrade to more recent JDKs It s not exactly correct either Even server java was not completely java 8+ there is a bunch of older big projects which still using java 6 you can check any Java survey for the last 5 years I agree Android is a big factor later but Android app a lot easier to migrate on Java 8 bytecode than a big enterprise server app it supported for at least 4 years on d8