Kotlin is an ergonomic language that runs on the Java Virtual Machine, among other targets. It is a joy to code for backend and is also the language of choice for Android development.

Designed to be short, this guide contains six carefully curated content pages. It presents material concisely to keep information close at hand and provides a way for experienced developers, especially Java developers, to quickly jump from a cursory introduction to being fully proficient in Kotlin. It covers the stable language features of Kotlin 2.2 focusing on the JVM platform.

(We have plans for future cheat sheets featuring the standard library and concurrency topics that are not covered here.)

What's inside:

• Basic Syntax
• Datatypes and Collection Factories
• Type Checking/Casting and Nullability
• Operators
• Functions
• Lambdas and SAM Constructors
• References
• Classes and Inheritance
• Data Classes
• Value Classes
• Objects
• Delegation
• Generics and Variance
• Enums and Sealed Classes
• Java Compatibility Annotations
• Annotation Targets
• KDoc Tags
• Exceptions

...and more

Author: Robert Pulsipher
Designer: Evelena Pulsipher
Publisher: Reusabit Software LLC
ISBN: 978-1-968995-00-3 (Loose Leaf)
Length: 6 pages (content)
Edition: 1st
Format: Loose Leaf, no holes
Publication Date: 2025-08-18