Kotlin Course

Kotlin is a statically typed language that runs on the Java Virtual Machine, fully interoperable with Java, but built from the ground up to fix the things about Java that had grown awkward — verbose boilerplate, no protection against null references, no way to write a quick script without a class wrapper. Google made it the preferred language for Android development in 2019, and it now shows up on backends and command-line tools too.

What you'll learn

You'll start with the fundamentals — variables, operators, conditionals, loops, functions — and immediately notice Kotlin trims ceremony Java requires: if and when work as expressions, functions can be one line, and semicolons are optional. From there the course covers Kotlin's defining feature, null safety, before moving into classes, data classes, and the functional-style collection operations (map, filter, lambdas) that show up in nearly every real Kotlin codebase.

Every lesson runs real, compiler-accurate code and shows its exact output, since Kotlin doesn't execute live in a browser — read each example closely, then try it yourself in the official Kotlin Playground or a local install.

Lessons

1. Introduction
2. Variables & Data Types
3. Operators
4. Conditionals
5. Loops
6. Functions
7. Null Safety
8. Classes & Objects
9. Data Classes
10. Collections & Lambdas