kotlin cheat sheet

Kotlin Cheat Sheet:

  1. Variables and Data Types: In Kotlin, you can declare variables using the "val" (immutable) or "var" (mutable) keywords. Kotlin has various data types, including Int, Double, Boolean, String, and more.

  2. Control Flow: Kotlin provides if-else expressions, when expressions (similar to switch statements in other languages), and for and while loops for controlling the flow of your program.

  3. Functions: In Kotlin, you can define functions using the "fun" keyword. Functions can have parameters and return types. You can also use default arguments and named arguments in Kotlin functions.

  4. Null Safety: Kotlin has built-in null safety features to help prevent null pointer exceptions. You can use the safe call operator (?.) and the Elvis operator (?:) to handle null values.

  5. Collections: Kotlin provides various collection types, such as arrays, lists, sets, and maps. You can perform operations like iteration, filtering, mapping, and sorting on collections using lambda expressions.

  6. Classes and Objects: Kotlin supports object-oriented programming and allows you to define classes and objects. You can use inheritance, interfaces, and data classes to create reusable and structured code.

  7. Extension Functions: Kotlin allows you to extend existing classes with new functions without modifying their source code. Extension functions can be useful for adding functionality to existing classes or libraries.

  8. Coroutines: Kotlin introduced coroutines to provide a simpler and more efficient way to write asynchronous code. Coroutines allow you to write asynchronous code in a sequential and structured manner.

  9. Lambdas: Kotlin supports lambda expressions, which are anonymous functions that can be used as arguments or return values. Lambdas are concise and powerful, enabling you to write functional-style code.

  10. Interoperability: Kotlin is fully interoperable with Java, which means you can use Kotlin code in existing Java projects and vice versa. Kotlin provides seamless integration with Java libraries and frameworks.

These are just some of the key features and concepts in Kotlin. By understanding and applying these concepts, you can effectively write Kotlin code and develop robust and efficient applications.