TypeScriptIntermediate
TypeScript (The Odin Project)
This section of The Odin Project's JavaScript path teaches TypeScript by having you retrofit type safety onto code you already wrote in vanilla JavaScript, rather than starting from a blank slate. You work through interfaces, generics, enums, and the type system's stricter checks, and come out able to add TypeScript to an existing project instead of just a fresh one. It suits learners who have already built something in JavaScript and want the next step, not total beginners who need JavaScript fundamentals first. Like the rest of Odin, there is no video or interactive editor: you read the material and do the exercises in your own local setup.