Node.js: Novice to Ninja
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    • Node.js: Novice to Ninja
    • Notice of Rights
    • Notice of Liability
    • Trademark Notice
    • About Craig Buckler
    • About SitePoint
    • Why Learn Node.js?
    • Summary
    • Quiz
    • Choosing a Node.js Version
    • How to Install Node.js on Linux (or Windows WSL2)
    • How to Install Node.js on macOS
    • How to Install Node.js on Windows
    • How to Install Node.js on Other Devices
    • Run JavaScript Commands in the Node.js REPL
    • Summary
    • Quiz
    • Your First Console App
    • Restarting Node.js Applications with Nodemon
    • What is Debugging?
    • How to Avoid Bugs
    • Node.js Debugging Environment Variables
    • Node.js Debugging Command-line Options
    • Console Debugging
    • Node.js util.debuglog
    • Debugging with Logging Modules
    • Node.js V8 Inspector
    • Debugging Node.js Apps with Chrome
    • Other Node.js Debugging Tools
    • Exercise: Debugging webhello.js
    • Summary
    • Quiz
    • Why use Express?
    • Create a New Node.js Project
    • Switch to ES6 Modules
    • Install Express
    • Create the Express Entry Script
    • Processing HTTP GET Query Strings
    • Global vs Local Packages
    • npm Help
    • npm Configuration
    • Project Initialization
    • Searching for Packages
    • Installing Packages
    • “No-install” Execution
    • Listing Packages
    • Finding Outdated Packages
    • Removing Packages
    • Using npm Scripts
    • Publishing Packages
    • Exercises
    • Summary
    • Quiz
    • CommonJS
    • ES2015 Modules (ESM)
    • Comparison of CommonJS and ES2015 Modules
    • Importing CommonJS Modules in ES2015
    • Requiring ES2015 Modules in CommonJS
    • Using ES2015 Modules in Browsers
    • Summary
    • Quiz
    • Single-threaded Non-blocking I/O Event-looping What?
    • The Event Loop
    • Callback Conundrums
    • Promises
    • async / await
    • Exercises
    • Summary
    • Quiz
    • A Database-driven Web Application Example
    • MongoDB
    • MySQL
    • Sequelize ORM
    • How to Choose the Right Database
    • Exercises
    • Summary
    • Quiz
    • What Are WebSockets?
    • Example WebSocket Chat Application
    • WebSocket Walkthrough
    • Advanced WebSockets Considerations
    • Exercise
    • Summary
    • Quiz
    • Process
    • OS
    • Util
    • URL
    • File System
    • Events
    • Streams
    • Worker Threads
    • Child Processes
    • Clusters
    • Exercises
    • Summary
    • Quiz
    • Source Code
    • Quizzing Quick Start
    • Summary
    • Why Develop Using Multiple Servers?
    • 1. One PostgreSQL Database Server
    • 2. Two Express HTTP Web Servers
    • 3. Three WebSocket Servers
    • 4. One Traefic Load Balancer
    • 5. Adminer Database Client
    • Docker Development Environment
    • Docker Production Environment
    • Summary
    • Database Library
    • Question Database Initialization
    • Starting a New Game
    • Joining a Game
    • Quiz Page
    • Summary
    • Initiating a WebSocket Connection
    • Game Logic
    • Exercises
    • Summary
    • Perfect Package Pursuit
    • Development Tools
    • Testing
    • Logging
    • Full-stack Frameworks
    • Server-side Frameworks
    • Web Publishing, Content Management Systems, and Blogging
    • Headless Content Management Systems
    • Static Site Generators
    • Database Drivers
    • Templating
    • Command Line
    • File System
    • Network
    • WebSockets
    • Images
    • Email
    • Security and Authentication
    • Summary
    • Pages vs Applications
    • Node.js Application Preparation
    • Dedicated Server Hosting
    • Static Site Hosting (Jamstack)
    • Serverless/Lambda Functions
    • Container Hosting
    • Summary
    • Is Node.js for You?
    • Is Deno Better?
    • Thank You for Reading!

What is Node.js?

Node.js is a JavaScript runtime, which means it runs programs written in JavaScript. Most developers use it to create command-line tools or web server applications.

Skip Ahead?

That’s everything you need know about Node.js. If you’re eager to start programming, skip ahead to Chapter 2. That said, it’s worth revisiting this chapter later to learn about Node’s advantages and core features.

JavaScript, JScript, ECMAScript, ES6, ES2015?

To make learning more confusing for beginners, JavaScript has many names. It started life as “Live Script” in 1994. Netscape rebranded it as “JavaScript” following a hasty deal with Sun Microsystems, despite it bearing little resemblance to Java or lightweight scripting. Microsoft couldn’t use that name, so it became JScript in Internet Explorer.

In 2005, Mozilla (which grew out of Netscape) joined ECMA International and standardized the language as “ ECMAScript ”. Versions 1 to 3 documented the evolution of JavaScript up until 1999. Version 4 was abandoned, but ECMAScript 5 became the standard supported by most browsers in 2009.

Work then started on ECMAScript 6—or “ES6”. The final specification was approved in 2015, which led to yet another name: “ES2015”. New specifications now arrive every year.

Rightly or wrongly, this course refers to “JavaScript” throughout. References to specific versions (such as ES9/ES2018) are only made if they affect the version of Node.js you need to use.

Node.js was initially developed by Ryan Dahl. He took the V8 JavaScript engine from Google’s Chrome browser, added some APIs, wrapped it in an event loop, and launched it as an open-source product on Linux and macOS in 2009. The Windows edition arrived in 2011.

The Node Package Manager (npm) was introduced in 2010. It allowed developers to use code modules published by others in their own projects. There was no official ECMAScript module standard at the time, so Node.js and npm adopted CommonJS.

The first (non-beta) release of Node.js arrived in 2015, with updates promised every six months.

Node.js wasn’t the first JavaScript runtime, but unlike other options—such as Rhino and SpiderMonkey —its popularity grew exponentially. Even those writing PHP, Python, Ruby or other languages often use Node.js tools to supplement their development processes.

Why Learn Node.js?

JavaScript is hugely popular on GitHub, and it’s ranked highly by developers. Companies including Netflix, Uber, Trello, PayPal, LinkedIn, eBay, NASA and Medium have adopted Node.js, and most professional developers will have encountered Node.js tools.

Below, we’ll look at some of the reasons you should consider using Node.js.

It’s JavaScript

JavaScript is used on trillions of web pages, where it has a browser monopoly. Every professional web developer requires JavaScript knowledge to program client-side applications.

Server-side languages are more diverse. Historically, developers could opt for PHP, Ruby, Python, C# (ASP.NET), Perl, or Java, but these have different syntaxes and concepts. It can be difficult to switch contexts, so larger project teams often split into frontend and backend developers.

Node.js allows a developer with frontend JavaScript knowledge to leverage their skills on the backend. It won’t make you a full-stack developer overnight, but the concepts are similar, and there’s less rigmarole when formatting JSON, handling character sets, using WebSockets, and so on.

JavaScript Alternatives

Some developers prefer languages such as TypeScript, PureScript, CoffeeScript, Reason, and Dart, which can transpile to JavaScript and run in a browser or Node.js. Ultimately, it still results in JavaScript code.

It’s Fast

Most server-side languages are fast enough, but few match the speed of Node.js. The V8 engine is quick, and it evolves rapidly, having the weight of Google and Chrome behind its development. Node.js also has a non-blocking, event-driven I/O.

Let’s go through that again with less jargon. Most languages use synchronous blocking execution. When you issue a command—such as fetching information from a database—that command will halt further processing and complete before the runtime progresses to the next statement. To ensure that multiple users can have access at the same time, web servers such as Apache create a new processing thread for every request. This is an expensive operation, and Apache has a default limit of 150 concurrent connections. Busy servers can become overloaded.

Node.js code (and browser JavaScript) runs on a single processing thread. Long-running tasks such as a database query are processed asynchronously, which doesn’t halt execution. The task runs in the background, and Node.js continues to the next command. When the task is complete, the returned data is passed to a callback function. A Node.js program can have many hundreds of ongoing operations that are completed whenever they’re finished, meaning that the processor is free to tackle other tasks.

Asynchronous programming has challenges, but it’s possible to create fast Node.js applications that scale well.

It’s Real-time

Web platform features such as WebSockets and server-sent events permit real-time functionality—such as instant data updates, live chat, multiplayer games, and more. These can be difficult to implement in traditional server-side languages, where they often require third-party services. Real-time functionality in Node.js is significantly easier.

It’s Lightweight

The Node.js runtime is small and cross-platform. As well as catering for Linux, macOS, and Windows, you find editions for embedded systems, the Raspberry Pi, and even SpaceX rockets.

It’s Modular

Node offers a minimal standard library with good documentation. It contains basic functions for error handling, file system access, network operations, and logging.

For everything else …

It’s Extendible

Node.js has the largest package registry in the world, with more than one million modules. You’ll find pre-written code for task runners, loggers, database connectors, image processors, code compilers, web servers, API managers, and even client-side libraries.

The npm command-line tool is provided with Node.js and makes it easy to install, update, and remove modules. You can also use it to install global modules so Node.js scripts can run as commands from anywhere on your system.

It’s Open Source

Node.js is an open-source project. The runtime is free to use without any commercial restrictions. The majority of modules are also free, because they’re submitted by the community for the benefit of other developers.

It’s Everywhere

This course concentrates on web applications, but you can use Node.js to create serverless functions, deployment scripts, cross-platform command-line tools, and even complex graphical apps such as VS Code, Slack, and Skype—all of which use the Electron framework.

As a web developer, you’ll almost certainly encounter Node.js, even if it’s not a core part of your technology stack. Knowing a little Node.js could help your projects and career. You’ll have a better insight into the possibilities available to modern web applications.

What About Deno?

Node.js is a cross-platform, V8-based JavaScript runtime released by Ryan Dahl in 2009.

Deno is a cross-platform, V8-based JavaScript runtime released by Ryan Dahl in 2020.

Deno smooths over some cracks and inconsistencies of Node.js, with the benefit of a decade’s worth of hindsight. It directly supports TypeScript without a compiler, uses ES6 modules rather than CommonJS, replicates many browser APIs (window, addEventListener, Fetch, Web Workers, etc.), and provides built-in tools for linting, testing, and bundling.

Deno is great—but it’s new, and yet to achieve a fraction of Node’s popularity. The frameworks are similar: if you know one, it’s easy to switch to the other.

Summary

In this chapter, you’ve learned that Node.js is a popular JavaScript runtime that’s uniquely suited to web development. I’ve summarized it in this chapter’s video. Chapter 2 describes how to install Node.js on your platform of choice.

Quiz

Many chapters in this course end with a quick quiz to ensure you’ve grasped the concepts. Beware! Some questions are designed to catch you out, so make sure you’ve been paying attention!

Community Questions