Getting Started With TypeScript

TypeScript compiles into JavaScript. JavaScript is what you are actually going to execute (either in the browser or on the server). So you are going to need the following:

alm editor window

TypeScript Version

Instead of using the stable TypeScript compiler we will be presenting a lot of new stuff in this book that may not be associated with a version number yet. I generally recommend people to use the nightly version because the compiler test suite only catches more bugs over time.

You can install it on the command line as

  1. npm install -g typescript@next

And now the command line tsc will be the latest and greatest. Various IDEs support it too, e.g.

  • alm always ships with the latest TypeScript version.
  • You can ask vscode to use this version by creating .vscode/settings.json with the following contents:
  1. {
  2.   "typescript.tsdk": "./node_modules/typescript/lib"
  3. }

Getting the Source Code

The source for this book is available in the books github repository https://github.com/basarat/typescript-book/tree/master/code most of the code samples can be copied into alm and you can play with them as is. For code samples that need additional setup (e.g. npm modules), we will link you to the code sample before presenting the code. e.g.

this/will/be/the/link/to/the/code.ts

  1. // This will be the code under discussion

With a dev setup out of the way let’s jump into TypeScript syntax.