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kotlinlang

In an Android project what's the purpose of `kotlinOptions.jvmTarget` ? I'm wondering because we don't write Java Code so what prevents me to set it to `16` ?

Bytecode generated for JDK 1.6 and 1.8 by Kotlin is quite different (in particular, lambdas &amp; default functions). In a regular JVM, that can create performance differences, JAR size differences, and interop differences. No idea if that's the case on Android though.

You can set target 16, but not sure that Android d8 supports desugaring of java 16 (though it does support at least java 14, but not all features and not all new additions to java standard library)

<https://developer.android.com/studio/write/java8-support|https://developer.android.com/studio/write/java8-support>

ok thanks, so the limiting factor is the D8 compiler (and the ART I guess). Then what confuses me, how can we know when and if Kotlin code poduces bytecode for, lets say Java 14, 15 or 16? It's important to know in order to set the right jvmTarget and to avoid breaking something

This option tells Kotlin compiler target JVM bytecode versions, there is version of bytecode in every .class file

&gt;  how can we know when and if Kotlin code poduces bytecode for, lets say Java 14, 15 or 16
<https://kotlinlang.org/docs/compiler-reference.html#jvm-target-version>

&gt;  to avoid breaking something
Yes, Android toolchain is the main limiting factor, check that it works thee first
This is full list features supported by D8 desugaring: <https://developer.android.com/studio/write/java8-support-table>

There is some level of native support on recent versions of Android, but as I understand it covers only Java 8