Mobile development

Stage 1 of 7 · 9 lessons · ~2 months

Kotlin fundamentals

Learn the language your apps will be written in before touching UI code. Null safety, collections and async code matter more on mobile than most beginners expect.

Start: val, var and type inference

Lessons· one lesson for each topic, in this order

  1. 1val, var and type inference
  2. 2Null safety
  3. 3Functions, lambdas and extensions
  4. 4Classes and data classes
  5. 5Sealed classes and when
  6. 6Collections and their operations
  7. 7Exceptions and Result
  8. 8Coroutine basics
  9. 9Gradle and dependencies

Start with· follow one of these

  • GuideFree
    Kotlin Documentation

    JetBrains

    Start with the Kotlin tour, then the null safety and coroutines basics pages

  • CourseFree
    Android Basics with Compose

    Google · Beginner

    The Kotlin pathways in Units 1 to 3 teach the language with practice sets

Practise

  • Exercism

    Dart, TypeScript, Kotlin and Swift tracks with small exercises and free mentor feedback

Keep handy

  • W3Schools

    Short Kotlin pages with a try-it editor for checking syntax quickly

Also worth your time

Before moving on: Solve 15 exercises on Exercism in your language, then write a small console program, such as a to-do list or a grade calculator, that uses classes, collections, error handling and one async call.

Tauseef's advice
Write Kotlin like Kotlin, not like Java with different keywords: data classes, null safety and collection functions. Coroutines only need the basics now; Unit 5 of Android Basics goes deeper when you need them.

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