1.2. REPL

REPL stands for Read-Eval-Print-Loop, and is a utility included with Node that can be very handy when you’re getting started. It works like the debug console in your browser and you can execute whatever commands you want. You don’t need to do anything to install it—you’ll have it available from the command line wherever Node is available. Before even creating an application you can start poking around and see what Node can do by typing node on the command line. If you don’t specify an application to run, you get the REPL instead.

After typing node at the command prompt, you can test a few simple lines of JavaScript, and they should evaluate as normal:

> ["Hello","World"].join(" ")
'Hello World'
> 2 + 3
5

You can exit the REPL by pressing Ctrl+C.