James Hibbard - Your First Week With Node.js

While there have been quite a few attempts to get JavaScript working as a server-side language, Node.js (frequently just called Node) has been the first environment that's gained any traction. It's now used by companies such as Netflix, Uber and Paypal to power their web apps. Node allows for blazingly fast performance; thanks to its event loop model, common tasks like network connection and database I/O can be executed very quickly indeed.

From a beginner's point of view, one of Node's obvious advantages is that it uses JavaScript, a ubiquitous language that many developers are comfortable with. If you can write JavaScript for the client-side, writing server-side applications with Node should not be too much of a stretch for you.

In this book, we'll offer a beginner's introduction to Node and its related technologies, and get you under way writing your first Node applications.

This book is for web developers who want to make a start using Node. It's assumed that you have a good understanding of JavaScript.

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So youve heard of Node.js, but arent quite sure what it is or where it fits into your development workflow. Or maybe youve heard people singing Nodes praises and now youre wondering if its something you need to learn. Perhaps youre familiar with another back-end technology and want to find out whats different about Node.

If that sounds like you, then keep reading. In this guide, Ill take a beginner-friendly, high-level look at Node.js and its main paradigms. Ill examine Nodes main use cases, as well as the current state of the Node landscape, and offer you a wide range of jumping off points (for further reading) along the way.

There are plenty of definitions to be found online. Lets take a look at a couple of the more popular ones. This is what the projects home page has to say:

Node.js is a JavaScript runtime built on Chromes V8 JavaScript engine.

And this is what Stack Overflow has to offer:

Node.js is an event-based, non-blocking, asynchronous I/O runtime that uses Googles V8 JavaScript engine and libuv library.

Hmmm, event-based, non-blocking, asynchronous I/Othats quite a lot to digest in one go. So lets approach this from a different angle and begin by focusing on the other detail that both descriptions mentionthe V8 JavaScript engine.

The V8 engine is the open-source JavaScript engine that runs in Google Chrome and other Chromium-based web browsers, including Brave, Opera, and Vivaldi. It was designed with performance in mind and is responsible for compiling JavaScript directly to native machine code that your computer can execute.

However, when we say that Node is built on the V8 engine, we dont mean that Node programs are executed in a browser. They arent. Rather, the creator of Node (Ryan Dahl) took the V8 engine and enhanced it with various features, such as a file system API, an HTTP library, and a number of operating systemrelated utility methods.

This means that Node.js is a program we can use to execute JavaScript on our computers. In other words, its a JavaScript runtime.