Introduction to Node.js

Overview

Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine. It enables the execution of JavaScript on the server side, allowing developers to build scalable network applications. Node.js uses an event-driven, non-blocking I/O model, making it lightweight and efficient.

Installation

To install Node.js, follow these steps:

1. Visit the Node.js official website.
2. Download the installer for your operating system.
3. Run the installer and follow the setup instructions.
4. Verify the installation by opening your terminal and typing:

node -v

You should see the installed version of Node.js.

Key Concepts

• Event Loop: Node.js operates on a single-threaded event loop which handles asynchronous operations.
• Modules: Node.js has a modular architecture, allowing you to include different functionalities via modules.
• NPM: Node Package Manager (NPM) is used to manage packages and dependencies in Node.js applications.

Code Example

Here’s a simple Node.js server example:

const http = require('http');

const hostname = '127.0.0.1';
const port = 3000;

const server = http.createServer((req, res) => {
    res.statusCode = 200;
    res.setHeader('Content-Type', 'text/plain');
    res.end('Hello World\n');
});

server.listen(port, hostname, () => {
    console.log(`Server running at http://${hostname}:${port}/`);
});
                

Save this code in a file called server.js and run it using:

node server.js

Visit http://127.0.0.1:3000 in your browser to see the output.

Best Practices

• Use asynchronous programming to avoid blocking the event loop.
• Handle errors gracefully using try-catch blocks or promise chaining.
• Keep your code modular by using modules and packages.
• Use environment variables to manage configuration settings.

FAQ