Using Node.js to Run JavaScript

Section 1.2: Setting Up the Environment

Tutorial 1.2.3: Using Node.js to Run JavaScript

Using Node.js to Run JavaScript

Node.js is a JavaScript runtime that allows you to execute JavaScript code outside of the browser. It's an essential tool for modern development, especially for server-side applications and command-line scripts. This tutorial will guide you through installing Node.js and running JavaScript with it.

Why Use Node.js?

• Run JavaScript Anywhere: Execute code on your computer, independent of the browser.
• Server-Side Development: Build APIs and back-end services.
• Access to npm: Use and manage libraries and tools through the Node Package Manager (npm).

Step-by-Step Guide

1. Download Node.js:

• Visit the official Node.js website.
• Download the LTS (Long Term Support) version for better stability.

1. Install Node.js:

• Run the downloaded installer and follow the installation prompts.
• Ensure that npm (Node Package Manager) is installed alongside Node.js (it usually is).

1. Verify Installation:

• Open your terminal (Command Prompt, PowerShell, or any terminal on macOS/Linux).
• Check the Node.js version:

     node -v

• Check the npm version:

     npm -v

Running JavaScript with Node.js

1. Using the REPL (Read-Eval-Print Loop):

• Open the terminal and type node to enter the Node.js interactive mode.
• Type JavaScript directly:

     > console.log("Hello, Node.js!");
     Hello, Node.js!

1. Running a JavaScript File:

• Create a new file named example.js and add the following code:

     console.log("Running JavaScript with Node.js!");

• Save the file and run it with Node.js:

     node example.js

• Output:

     Running JavaScript with Node.js!

Exploring Node.js Features

1. Accessing the File System:

• Example of reading a file:

     const fs = require('fs');
     fs.readFile('example.txt', 'utf8', (err, data) => {
       if (err) throw err;
       console.log(data);
     });

1. Using npm:

• Install a package:

     npm install lodash

• Use it in your code:

     const _ = require('lodash');
     console.log(_.capitalize("hello world"));

Benefits of Using Node.js for JavaScript

• Fast Execution: Powered by Google’s V8 engine.
• Asynchronous and Event-Driven: Ideal for non-blocking applications.
• Cross-Platform: Runs on Windows, macOS, and Linux.