Since 2017 Kotlin has become the official language for creating Android applications, but there are still many applications and developers using Java or having legacy code written in Java. Let’s look at the the differences between Java and Kotlin, features that are new in Kotlin and review some tips on how to switch existing Java applications to Kotlin. Kotlin and Java are fully interchangeable so they can be mixed together in one project.

Main syntax differences

Let’s view some parts of a code written in Java and it’s analogue in Kotlin.

First of all, you can notice that there are no semicolons…