JavaScript Setup & Environment

Option 1: Browser Console (Instant, No Install)

The fastest way to run JavaScript is already in your browser. Every modern browser ships with a full JavaScript runtime and developer tools.

1. Open Google Chrome or Firefox
2. Press F12 (Windows/Linux) or Cmd+Option+J (Mac)
3. Click the Console tab
4. Type console.log("Hello!") and press Enter

// Type these in the browser console:
console.log("Hello, World!");
console.log(2 + 2);
console.log(typeof "hello");

// Multi-line object inspection
const user = { name: "Alex", age: 28 };
console.log(user);

Option 2: Install Node.js (Run JS Anywhere)

Node.js lets you run JavaScript files from the terminal - no browser needed. It also comes with npm, which you will need for installing packages.

Install Steps (Windows / Mac / Linux)

1. Go to nodejs.org and download the LTS version (Node 20+)
2. Run the installer and follow the prompts (default settings are fine)
3. Open a terminal and verify the install:

node --version   # should print v20.x.x or higher
npm --version    # should print 10.x.x or higher

VS Code Setup for JavaScript

Visual Studio Code is the industry-standard editor for JavaScript development. It is free, fast, and has excellent built-in JavaScript support.

Install VS Code

1. Download from code.visualstudio.com and install
2. Open VS Code and install these extensions:

Configure Auto-format on Save

Open VS Code settings (Ctrl+,) and add these to settings.json:

{
    "editor.formatOnSave": true,
    "editor.defaultFormatter": "esbenp.prettier-vscode",
    "editor.tabSize": 2,
    "javascript.preferences.quoteStyle": "single"
}

Run Your First JS File

Create a file called hello.js and run it with Node.js:

const name = "RubanLearn";
const year = new Date().getFullYear();

console.log(`Welcome to ${name}!`);
console.log(`Learning JavaScript in ${year}.`);

// Simple function
function greet(person) {
    return `Hello, ${person}!`;
}

console.log(greet("Developer"));

node hello.js

package.json Basics

Every Node.js project has a package.json file that tracks the project name, version, and dependencies. Create one with:

mkdir my-project && cd my-project
npm init -y          # creates package.json with defaults
npm install lodash   # install a package (example)

Online Editors (No Install)

For quick experiments without any local setup:

• CodePen - best for HTML/CSS/JS experiments with live preview
• JSFiddle - classic JS sandbox, easy to share
• StackBlitz - full VS Code in the browser, supports Node.js projects
• Replit - full development environment, supports Node.js
• PlayCode.io - fast JS playground with instant output