IntelliJ IDEA is used as a development environment, either Community or Ultimate Edition. This can be downloaded here: www.jetbrains.com/idea/download.

Make sure that the latest Java Development Kit (JDK) is installed and configured in our system. Download the JDK here: www.oracle.com/technetwork/java/javase/downloads/index.html.

The code for this chapter can be downloaded here: https://github.com/PacktPublishing/Hands-On-Object-Oriented-Programming-with-Kotlin/tree/master/src/main/kotlin/Chapter01.