Let's start writing some TypeScript!
In the following sections, we will take a look at different snippets showing some of the features of TypeScript. In order to be able to run the snippets and play with them yourself, you'll need to install the TypeScript compiler on your computer. Let's take a look at how to do this.
TypeScript is best installed using Node Package Manager (npm). I'd recommend that you use npm's version 3.0.0 or newer. If you don't have node.js and npm installed already, you can visit https://nodejs.org and follow the instructions there.
Once you have npm installed and running, verify that you have the latest version by opening your terminal window and running the following command:
$ npm -v
Use the following command in order to install TypeScript 2.1.0 or newer:
$ npm install -g typescript@^2.1.0
The preceding command will install the TypeScript compiler and add its executable (tsc) as global.
In order to verify that...