1, it is optional. That is, it does not let you completely abandon JS, and jump to another completely different language. You can even change the source code file from the JS suffix to the TS suffix to start enjoying the benefits of typescript.
2, compatible with ECMAScript standard. In particular, the latest version of TS is designed to be fully compatible with ES6. The benefit of this is that developers can use TS to advance the new features of ES6 and migrate easily to ES6 in the future.
3, excellent tool support. In addition to the universe first ide--visual studio has native support for it, there are also eclipse plug-ins available, webstorm recently enhanced typescript support, of course, there is no lack of sublime text plug-in available.
4, more frameworks for support. Many frameworks are used or can be implemented using typescript. For example, the domestic HTML5 3D game engine "White Crane", or Telerik Nativescript (a mobile app using JS for cross-platform development framework) can also use typescript to develop.
Typescript usage Analysis