Kotlin is an open source programming language for JVM and Android that combines OO and functional features and is focused on interoperability, safety, clarity and tooling support. It’s developed on GitHub under the Apache 2.0 license and currently has more than 100 contributors.
Being a general-purpose language, Kotlin works everywhere where Java works: server-side applications, mobile applications (Android), desktop applications. It works with all major tools and services such as
- IntelliJ IDEA, Android Studio and Eclipse
- Maven, Gradle and Ant
- Spring Boot
- GitHub, Slack
Kotlin has been mature and ready for production for quite some time. JetBrains have been using Kotlin in real-life projects on a rather extensive scale over the last two years.
Kotlin enables you to avoid entire classes of errors such as null pointer exceptions.
Get rid of those pesky NullPointerExceptionse:
var output : String
output = null
Kotlin protects you from mistakenly operating on nullable types, including those from Java:
How to start
The easiest way to play with the language is through its online mini-IDE: try.kotl.in, including Koans — a set of introductory problems which guide you through the basics of the language.
To use Kotlin on your machine (and Koans can be completed offline as well):
- IntelliJ IDEA (Ultimate or Community): just create a Kotlin project or a Kotlin file in a Java project
- Android Studio: install the plugin through Plugin Manager
- Eclipse: install the plugin through Marketplace.
Here’s a video of Kotlin in action: