The compile-time checks are possible because, in TypeScript, you have implicitly datatyped the variable holding the function just by storing the function in the variable.

TypeScript provides native support both for organizing your application's client-side code into a set of modules, and for freeing you from having to manage the resulting script tags.

TypeScript. By default TypeScript compiles to JavaScript, meaning that it could in turn be compiled to WebAssembly.

The key difference between JavaScript and TypeScript, however, is the type checker. Upon compilation, every TypeScript-program gets checked on whether the data types are consistent with one another.

Microsoft's TypeScript 3.9 JavaScript spin-off brings major compile time improvements for popular JavaScript libraries.

A subset of TypeScript itself, AssemblyScript gives developers with a background in TypeScript and standard JavaScript APIs a way to compile to WebAssembly.

On March 11, 2025, Microsoft announced that they are developing a new tool that will compile TypeScript in one-tenth the time, and are aiming to release it within 2025.