Welcome to our tour of Kotlin! | Kotlin

Quickly learn the essentials of the Kotlin programming language through our tours. Grasp the fundamentals with the beginner tour. Deepen your understanding with the intermediate tour.

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• Hello world

  Basic types

  Collections

  Control flow

  Functions

  Classes

  Null safety

• Extension functions

  Scope functions

  Lambda expressions with receiver

  Classes and interfaces

  Objects

  Open and special classes

  Properties

  Null safety

  Libraries and APIs

15 April 2026