In the six months since Google announced official support for Kotlin as a first-class language for Android development, Kotlin usage has more than doubled, writes Google product manager James Lau, and more than 17% of Android Studio 3.0 projects now use Kotlin.
The figures provided by Lau are consistent with a recent Realm report claiming that about 15% of Android developers are using Kotlin and 20% of apps are being ported from Java to Kotlin. Additionally, Realm predicts that 50% of Android developers will be using Kotlin by the end of 2018.
Google, as Lau explains, has been working in the last few months to improve Kotlin support for Android development. In particular, as InfoQ already reported, Android Studio 3.0 has got stable support for Kotlin, including the creation of new Kotlin files or the conversion of Java code to Kotlin. Additionally, Android Studio 3 is able to translate Java snippets into Kotlin by just pasting them into a Kotlin file.
Another significant improvement concerns the addition of nullability annotations to the Android Support Library. In fact any Java reference can be null, thus defeating Kotlin’s special requirements to handle null values. Nullability annotations will provide the Kotlin compiler with enough information to properly handle nullable and non-nullable variables.
As a final note, Google has also published a couple of guides meant to provide guidance for Android developers interested in using Kotlin. In particular, the Kotlin Style Guide collects rules and coding standard, including naming conventions, formatting, etc. The Interop guide focuses on best practices when creating APIs in either Java or Kotlin so that their usage feels idiomatic in both languages.
If you are interested in trying out Kotlin for Android development, you might want to check what remains to do to provide a better Kotlin experience before jumping on the Android Studio 3 bandwagon.