Announcing TypeScript 2.8

App Center Team

Today we’re excited to announce and get some early feedback with TypeScript 2.8’s Release Candidate. To get started with the RC, you can access it through NuGet, or use npm with the following command:

npm install -g typescript@rc

TypeScript 2.8 introduces a new construct called conditional types. This new construct is based on JavaScript’s conditional syntax, and takes the form A extends B ? C : D. You should mentally read this as “if the type A is assignable to B, then the type boils down to C, and otherwise becomes D“.