Cheat Sheets
Java
Java is one of the most popular programming languages in the world. With Java you can build various types of applications such as desktop, web, mobile apps and distributed systems.
Java Cheatsheet - Moshfegh Hamedani
Java Cheatsheet - CodeWithHarry
Kotlin
Kotlin is a modern, trending programming language. It is easy to learn, especially if you already know Java (it is 100% compatible with Java). It is used to develop Android apps, server side apps, and much more.