Beginner · Free · In your browser
Learn JavaScript
Go from first expressions to reliable data features. Build a progress report, then explore immutable updates, sorting, validation, and debugging before creating a course recommendation engine.
No installation. Your code runs right in the browser. No previous experience required. A little curiosity is enough.
What you will be able to do
- Use values, conditions, loops, and reusable functions
- Transform records without changing the original data
- Validate input and test boundary cases
- Build a progress report and a course recommendation engine
Course outline
Values & first steps
Build a reliable foundation in values, variables, and types.
Decisions & reusable work
Choose a path, repeat work, and write functions.
Collections & meaningful data
Select records, model objects, and normalize text.
Reliable features
Handle bad data, aggregate records, and build your final report.
Reliable data pipelines
Unpack records, make deliberate copies, transform collections, and sort with a rule.
Design, validate & debug
Set input contracts, explain failures, repair shared state, and build a recommendation feature.
Ready for your first line?
Every lesson is short, hands-on, and checked automatically.
Start learning JavaScript →