TypeScript after JavaScript
Add types to familiar code and make function contracts clearer.
Prerequisite: JavaScript foundations · 59 minutes of guided study
6 published lessons, from first principles to a small project.
Start first lesson →What you’ll be able to do
- Objects group related properties.
- Combine loops, objects, conditions, and functions.
How to study this course
Follow the numbered modules. Read the example, explain why it works, attempt the exercise, then compare your result with the supplied checks.
Setup: A modern browser. JavaScript, TypeScript, Python and SQLite exercises run here; project workshops state their additional setup.
Times estimate guided reading and practice. Projects and revision can take longer.
Course syllabus · 6 lessons
1 · Write contracts
2 · Model and build
- Narrow a union8 min · Browser exercise →
Arrays store values in order, starting at index zero.
- Keep a type relationship8 min · Browser exercise →
Arrays store values in order, starting at index zero.
- Project · Typed expense summary20 min · Browser exercise →
Combine loops, objects, conditions, and functions.