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Kotlin Fundamentals

Learn Kotlin, JetBrains' JVM language behind modern Android and a clean alternative to Java on the backend. Covers val and var, numeric types and conversions, string templates, null safety, if and when, loops and ranges, functions, lambdas and higher-order functions, lists, maps, sets, sequences, classes and constructors, data and sealed classes, and inheritance with interfaces. Every lesson ends in a hands-on exercise compiled and run by a real Kotlin compiler.

beginner19 lessons6 chapters19 graded exercisesKotlin
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What you’ll be able to do

Chapter by chapter. Every lesson ends in a graded exercise.

  • Getting Started
  • Strings and Null Safety
  • Control Flow
  • Functions and Lambdas
  • Collections
  • Classes and Inheritance
Taught in Kotlin, graded on a real executor.

Curriculum

6 chapters, 19 lessons. Each lesson is a short read and a graded exercise.

  1. 1Hello, WorldRead · exercise
  2. 2val and varRead · exercise
  3. 3Numbers and MathRead · exercise