A complete TypeScript curriculum covering everything from basic types to compiler internals, split into 5 sections and 106 chapters. It starts with foundations — primitives, unions, narrowing, and the type system’s core rules — then moves into intermediate territory: classes, generics, mapped types, conditional types, and the full utility-type toolkit. The advanced section goes deep into variance, branded types, and type-level programming patterns, while the modules/async section handles declaration files, path mapping, promises, and runtime validation. The final section covers tooling, decorators, compiler flags, framework integrations, migration strategies, and a capstone project, making it suitable for beginners who want full coverage and experienced developers who want to fill in gaps.
TypeScript is a typed superset of JavaScript that compiles to plain JavaScript. Every valid JavaScript program is already a valid TypeScript program — TypeScript just adds a layer of static types on top, checks them at build time, and strips them away before the code ever runs in a browser or Node. It was created…
Before writing any TypeScript, you need a working environment — Node.js, npm, the TypeScript compiler, and a code editor that understands the language. This is a one-time investment, but it’s the foundation everything else builds on. Get it right and every subsequent step is smooth; get it wrong and you’ll spend hours chasing phantom errors…
The TypeScript CLI (tsc) is the program that reads your .ts files, type-checks them, and emits .js. But tsc on its own does almost nothing useful — it needs configuration. That configuration lives in tsconfig.json, a single file at the project root that tells the compiler which files to include, what JavaScript version to target,…
TypeScript’s type system starts with a small set of primitive types: string, number, boolean, null, and undefined. These are the atoms — every more complex type is built by combining them. They map directly to JavaScript’s runtime primitives, but TypeScript gives them a compile-time identity that the runtime doesn’t have. Understanding them properly is not…
Once you have the primitives, the next step is collections and named values. Arrays hold many values of the same type. Tuples hold a fixed number of values of different types, position by position. Enums give names to a set of related constants. These three types appear constantly — arrays in every list, tuples in…