TypeScript is a statically typed superset of JavaScript that compiles to plain JavaScript. It can help you be more productive and write higher quality code. That's all great, but migrating an existing JavaScript project to TypeScript can seem like a daunting proposition.

Luckily, benefiting from TypeScript doesn't require you to migrate your entire project to TypeScript. You can benefit from TypeScript by making incremental changes to your project.

In this module, you'll learn the basics of the TypeScript language and how to incrementally migrate a project to TypeScript. You'll also see how Visual Studio 2017 leverages the TypeScript Language Service to provide a rich JavaScript development experience including features such as symbol-based navigation, statement completion, and code refactoring. And you'll see how to use JSDoc comments and TypeScript Declaration (d.ts) files to refine the TypeScript Language Service's understanding of your code.