crossoverjie/from-java-to-kotlin — explained in plain English
Analysis updated 2026-08-08 · repo last pushed 2017-05-22
Look up the Kotlin equivalent of a Java pattern you already know, like declaring a variable or writing a loop.
See how a verbose Java data class with getters, setters, and equals collapses to a single line in Kotlin.
Quickly find the right Kotlin keyword when you forget whether Java's final maps to val or const.
Browse the Chinese version of the cheat sheet if you prefer reading documentation in Chinese.
| crossoverjie/from-java-to-kotlin | 0verflowme/intech-sol | abhishek-kumar09/configurate | |
|---|---|---|---|
| Language | Java | Java | Java |
| Last pushed | 2017-05-22 | 2022-11-16 | 2020-09-30 |
| Maintenance | Dormant | Dormant | Dormant |
| Setup difficulty | easy | hard | easy |
| Complexity | 1/5 | 1/5 | 2/5 |
| Audience | developer | developer | developer |
Figures from each repo's GitHub metadata at analysis time.
No setup required, it is a Markdown cheat sheet you read directly in the README.
From Java To Kotlin is a side-by-side cheat sheet that helps Java developers quickly learn the equivalent Kotlin syntax for common programming tasks. Instead of reading a full tutorial or textbook, you can scan this reference and immediately see how something you already know in Java translates into Kotlin. The project is structured as a long series of paired code snippets. Each section shows a familiar Java pattern on the left, like writing an if-statement, looping through a list, or defining a class with getters and setters. On the right, you see the Kotlin version of that exact same code. The examples cover everyday basics: printing text, declaring variables, handling null values, string interpolation, type casting, loops, collections, functions, and data classes. By comparing the two, you can absorb Kotlin's syntax and idioms without needing to start from scratch. This is aimed at Android developers or backend Java developers who are migrating to Kotlin and want a quick mental map. For example, if you have spent years writing Java and your team just switched to Kotlin, you might forget whether the keyword for a constant is final or val. You glance at the cheat sheet, see the pairing, and move on. The data class example is especially compelling: a class with fields, a constructor, getters, setters, equals, hashCode, and toString in Java collapses to a single line in Kotlin, and seeing that side by side is a fast way to understand the appeal of the newer language. The project is straightforward and intentionally minimal. There is no deep prose explaining language theory or design philosophy, it is purely a lookup table. The README also links to a Chinese version, which broadens its accessibility. Contributions are welcome via pull requests, so the community can add more comparison examples over time. If you are transitioning from Java to Kotlin or just curious how the two languages compare for routine programming tasks, this cheat sheet gets you oriented quickly without wading through documentation.
A side-by-side cheat sheet that shows Java developers the equivalent Kotlin syntax for common programming tasks like loops, null handling, and data classes, so you can learn Kotlin by comparing it to what you already know.
Mainly Java. The stack also includes Java, Kotlin, Markdown.
Dormant — no commits in 2+ years (last push 2017-05-22).
Setup difficulty is rated easy, with roughly 5min to a first successful run.
Mainly developer.
This repo across BitVibe Labs
Verify against the repo before relying on details.