Beginner Code District

Kotlin

Modern Android development.

Kotlin is the language Google recommends for Android, and it runs everywhere Java runs. It is concise, protects you from null crashes and works side by side with Java code. This course starts from zero with Kotlin 2: values and string templates, null safety, if and when expressions, ranges and loops, functions with default and named arguments, then classes and data classes, collections and lambdas, extension functions, a gentle first look at coroutines and a glimpse of Jetpack Compose.

Every lesson is short and packed with quizzes, so you learn by doing.

Lessons: 14
Time: 2 h
Level: Beginner

Start the track · Hello, Kotlin

Bronze open
Silver open
Gold locked

Ready to prove it?

Three exams are waiting: Bronze, Silver and Gold.

Go to the exams

What you'll be able to do

Write and run Kotlin programs with val, var and string templates
Handle missing values safely with nullable types, ?. and ?:
Write clear functions with default and named arguments
Model data with data classes and transform collections with filter, map and groupBy
Understand coroutines and read a simple Jetpack Compose screen

The journey

1
Module 1
Kotlin basics

Your first program, val and var, null safety, when, ranges and functions.

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2
Module 2
Classes and collections

Data classes, collections and lambdas, coroutines and a first Compose screen.

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3
Module 3
Next steps

A full Android app, Kotlin Flow, server-side Kotlin and shared code.

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