Kotlin
The modern default language for Android.
Kotlin is taught here in 3 lessons, running from Syntax and null safety through to Coroutines and collections. Each lesson takes one topic, shows the working code, and links onward to the next, so the course can be read straight through in order.
| Track | Mobile Development |
| Lessons | 3 |
| Level | Beginner |
| Reading time | about 39 minutes |
| Prerequisites | Helpful, but not required: React Native |
Lessons
- Syntax and null safetyvals and vars, expression-oriented control flow, and the type system that keeps null out of your code until you ask for it.
- Classes, data classes and extensionsPrimary constructors, inheritance and interfaces, then the language features that remove boilerplate: data classes, sealed types and extension functions.
- Coroutines and collectionsSuspend functions without blocking a thread, structured concurrency, Flow for streams, and the collection operators you will use daily.
More in Mobile Development
Android iOS Flutter React Native Swift
FAQ
How long does the Kotlin course take?
It has 3 lessons, about 39 minutes of reading. Expect roughly twice that if you type out and run every example.
Do I need prior experience for Kotlin?
Not strictly. It helps to have read React Native first, because some lessons build on it, but every lesson explains its own assumptions.
What should I read after Kotlin?
Continue with Swift (3 lessons), the next course in Mobile Development.
Last refreshed 2026-09-18.