TypeScript enhances JavaScript with types, and with features that are only available in the more recent ECMAScript standards. You may install the TypeScript SDK in Visual Studio to take advantage of the same user interface you are used to with C#, or you may install it with Node.js. Adding TypeScript to your ASP.NET projects is straightforward; it is enough to add .ts files to it. Compiler options may be specified within Visual Studio project options, or with a specific JSON configuration file. According to the compiler settings, JavaScript files are generated either on saving the respective .ts files or when the project is built, and may be placed in your Views in the usual way.
TypeScript declarations are very similar to JavaScript declarations, the only differences being that they are obligatory and are the specifications of types. Simple types are the same as JavaScript, with only the addition of any, unknown, void, never, and the C#-like enum.
Scoping rules include let and const ECMAScript 6 block-level scoping, together with the usual var-based scoping.
TypeScript enhances JavaScript expressions with type assertions and ECMAScript 6 string interpolation.