Node.js is a powerful JavaScript runtime built on Chrome's V8 JavaScript engine. It allows developers to run JavaScript on the server side, making it a popular choice for building scalable network applications. Node.js is crucial for modern web development, offering an event-driven, non-blocking I/O model that makes it lightweight and efficient. This article will guide you through the process of installing and running Node.js on a Linux system, ensuring you can leverage its capabilities in your development environment.

Examples:

1. Installing Node.js on Linux

   To install Node.js, you can use the NodeSource binary distributions repository. Follow these steps:

   • Update your package index:

     sudo apt update

   • Install Node.js:

     curl -fsSL https://deb.nodesource.com/setup_16.x | sudo -E bash -
     sudo apt-get install -y nodejs

   This will install the latest LTS (Long Term Support) version of Node.js.

2. Verifying the Installation

   After installation, you can verify that Node.js and npm (Node Package Manager) are installed correctly by checking their versions:

   node -v
   npm -v

   You should see the version numbers of Node.js and npm printed on your terminal.

3. Creating a Simple Node.js Application

   • Create a new directory for your project:

     mkdir my-node-app
     cd my-node-app

   • Initialize a new Node.js project:

     npm init -y

     This command creates a package.json file with default settings.

   • Create an index.js file:

     touch index.js

   • Open index.js in a text editor and add the following code:

     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}/`);
     });

4. Running the Node.js Application

   • Run the application using Node.js:

     node index.js

   • Access the application: Open your web browser and navigate to http://127.0.0.1:3000/. You should see "Hello World" displayed on the page.

5. Installing Additional Packages

   • Install Express.js (a popular web framework for Node.js):

     npm install express

   • Modify index.js to use Express:

     const express = require('express');
     const app = express();
     const port = 3000;
     
     app.get('/', (req, res) => {
     res.send('Hello World!');
     });
     
     app.listen(port, () => {
     console.log(`Example app listening at http://localhost:${port}`);
     });

   • Run the application again:

     node index.js

   • Access the application: Open your web browser and navigate to http://localhost:3000/. You should see "Hello World!" displayed on the page.