What lives here
One hundred short lessons, one unbroken chain: every page ends with a link to the next one, so you can read the course start to finish without ever wondering where to click. Each lesson teaches one idea with short TypeScript examples, and the longer deep dives live on their own pages under JavaScript:
- Start here: What is TypeScript and where it runs — then follow the chain through lesson 100.
- Language core, lessons 2-30: install, first program, tsconfig, basic types, any and unknown, arrays, aliases, interfaces, unions, functions, generics, classes, enums, modules, decorators.
- Types and tooling, lessons 31-60: discriminated unions, mapped and conditional types, utility types, tsc, strict mode, declarations, linting, Node, files, JSON, timers, process.
- Async and quality, lessons 61-80: promises, async and await, HTTPS, event loop, assert tests, fixtures, DOM, fetch, forms, storage.
- Finish, lessons 81-100: npm, validation, iterators, branding, builders, streams, three capstones (todo CLI, JSON API, utils library), modern TypeScript tour, and the hero roadmap with every lesson on one page.
How to use this course
Type every example, do not just read it. Compile each snippet with
tsc before moving on - the course assumes
your hands remember lesson 3 by the time lesson 16 arrives.
Keep strict on from day one: the compiler
is a patient teacher that never sleeps.