Microsoft Releases TypeScript 4.0

Microsoft has announced the release of TypeScript 4.0, the latest major version of its open-source superset of JavaScript.

“TypeScript 4.0 represents our next generation of TypeScript releases, as we dive deeper into expressivity, productivity, and scalability,” Microsoft’s Daniel Rosenwasser writes in the announcement post. “With TypeScript 4.0, there are no major breaking changes. In fact, if you’re new to the language, now is the best time to start using it.”

For those unfamiliar, Rosenwasser has a nice explanation of the why of TypeScript:

“TypeScript is a language that builds on top of JavaScript by adding syntax for static types,” he writes. “The idea is that by writing down the types of your values and where they’re used, you can use TypeScript to type-check your code and tell you about mistakes before you run your code (and even before saving your file). You can then use the TypeScript compiler to then strip away types from your code, and leaving you with clean, readable JavaScript that runs anywhere. Beyond checking, TypeScript also uses static types to power great editor tooling like auto-completion, code navigation, refactorings, and more. In fact, if you’ve used JavaScript in an editor like Visual Studio Code or Visual Studio, you’ve already been using an experience powered by types and TypeScript.”

TypeScript was created by Anders Hejlsberg, my personal hero and the lead architect of C#, Delphi/Object Pascal, and Turbo Pascal, so he’s somewhat experienced designing programming languages. It answers a real problem with JavaScript and, as such, its popularity has surged in recent years. The language saw over 50 million monthly downloads for the first time in July, and it is now ranked as the second-most-loved language by StackOverflow.

You can learn more about TypeScript on the TypeScript website.