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Module 1: Introduction to JavaScriptModule 1: Introduction to JavaScript4
❯

  1. 1What is JavaScript?
  2. 2Set Up JavaScript Environment
  3. 3JavaScript Hello World Program
  4. 4JavaScript in the Browser vs Node.js

Module 2: JavaScript BasicsModule 2: JavaScript Basics10
❯

  1. 1JavaScript Variables
  2. 2JavaScript Data Types
  3. 3JavaScript Type Conversion
  4. 4JavaScript Operators
  5. 5JavaScript Expressions
  6. 6JavaScript Conditional Statements
  7. 7JavaScript Loops
  8. 8JavaScript For Loop
  9. 9JavaScript While Loop
  10. 10JavaScript do while Loop Explained with Examples

Module 3: Functions and ScopeModule 3: Functions and Scope7
❯

  1. 1JavaScript Functions
  2. 2JavaScript Function Expressions
  3. 3JavaScript Arrow Functions
  4. 4JavaScript Scope – Global, Local, Block
  5. 5JavaScript Lexical Scope
  6. 6JavaScript Hoisting
  7. 7JavaScript Closures Explained – Inner Functions, Lexical Scope & Examples

Module 4: Objects and ArraysModule 4: Objects and Arrays6
❯

  1. 1JavaScript Objects – Complete Guide for Beginners and Beyond
  2. 2JavaScript Arrays – Basics to Advanced with Examples
  3. 3JavaScript Array Methods
  4. 4JavaScript Destructuring Assignment
  5. 5JavaScript Iterating Over Objects
  6. 6Spread and Rest Operators in JavaScript

Module 5: The Document Object Model (DOM)Module 5: The Document Object Model (DOM)7
❯

  1. 1JavaScript DOM Tree
  2. 2JavaScript Selecting Elements in DOM
  3. 3JavaScript Modifying Content – Text, HTML, and Attributes Explained
  4. 4JavaScript Remove All Links from the Document
  5. 5JavaScript Event Handling
  6. 6JavaScript Create Elements – DOM
  7. 7JavaScript Remove Elements – Remove DOM Elements Easily

Module 6: ES6+ Modern JavaScriptModule 6: ES6+ Modern JavaScript4
❯

  1. 1JavaScript Template Literals – Syntax, Examples, Expressions, and Nesting
  2. 2Enhanced Object Literals in JavaScript - ES6 Features
  3. 3JavaScript Classes and Inheritance - ES6 OOP
  4. 4JavaScript Modules - import & export

Module 7: Asynchronous JavaScriptModule 7: Asynchronous JavaScript5
❯

  1. 1JavaScript Callbacks and Callback Hell
  2. 2JavaScript Promises - Creating and Chaining
  3. 3JavaScript Async/Await - Simplify Promises
  4. 4Fetch API in JavaScript - Get & Post Data
  5. 5Error Handling in Async JavaScript - Async/Await, Promises, Try-Catch

Module 8: Error Handling and DebuggingModule 8: Error Handling and Debugging3
❯

  1. 1JavaScript Error Types - Try Catch, ReferenceError, TypeError
  2. 2try, catch, finally in JavaScript
  3. 3Console API and Debugging in Browser - JavaScript Debugging Tools

Module 9: Browser APIs and Local StorageModule 9: Browser APIs and Local Storage5
❯

  1. 1JavaScript Browser APIs
  2. 2Local Storage in JavaScript - Store and Retrieve Data
  3. 3JavaScript Session Storage
  4. 4Manipulating URL and Browser History in JavaScript
  5. 5JavaScript Timers - setTimeout vs setInterval

Module 10: JavaScript and the WebModule 10: JavaScript and the Web4
❯

  1. 1JavaScript Form Validation - Validate User Input with Pure JS
  2. 2JavaScript DOM Events and Event Delegation
  3. 3Creating Interactive UI Elements with JavaScript
  4. 4JavaScript Fetch API - Get and Post Data

Module 11: Real-World JavaScript ProjectsModule 11: Real-World JavaScript Projects4
❯

  1. 1To-Do List App in JavaScript - Build a Console-Based Task Manager
  2. 2Build a Weather App Using API in JavaScript
  3. 3Simple Quiz Application in JavaScript
  4. 4JavaScript Budget Tracker Project - Expense Manager with Pure JavaScript

Hello World in JavaScript
Using Console, Node.js & VS Code

Introduction

Every programming journey begins with a humble start — the "Hello, World!" program. In JavaScript, this tiny snippet introduces you to the syntax, output methods, and the environments in which JavaScript runs. Whether you're using the browser console, Node.js, or Visual Studio Code, this guide walks you through it all.

1. JavaScript Hello World in the Browser Console

This is the fastest and most accessible way to run JavaScript without any installation.

Step-by-Step:

  1. Open Google Chrome or any modern browser.
  2. Right-click anywhere on the page and choose Inspect.
  3. Go to the Console tab.
  4. Type the following code and press Enter:

console.log("Hello, World!");

Output:

Hello, World!

Explanation: console.log() is a JavaScript function used to print messages to the console — great for debugging or quick testing.

2. Hello World using Node.js

Node.js is a JavaScript runtime that allows you to run JS outside the browser, typically for backend development.

Step-by-Step:

  1. Install Node.js from the official website: https://nodejs.org.
  2. Open your terminal or command prompt.
  3. Create a new file named hello.js using a code editor or touch hello.js on terminal.
  4. Add the following code:

// hello.js
console.log("Hello, World from Node.js!");

To Run:


node hello.js

Output:

Hello, World from Node.js!

Explanation: When you run node hello.js, Node.js executes the script file and outputs the result to your terminal.

3. Hello World using Visual Studio Code (VS Code)

VS Code is a lightweight, powerful code editor perfect for writing and testing JavaScript projects.

Step-by-Step:

  1. Download and install VS Code.
  2. Open VS Code and create a new folder (e.g., HelloWorldProject).
  3. Create a file inside it named hello.js.
  4. Write the following code:

// hello.js
console.log("Hello from Visual Studio Code!");

Run the Script:

  1. Open the terminal in VS Code (use Ctrl + `).
  2. Run the script using:

node hello.js

Output:

Hello from Visual Studio Code!

Tip: If you see an error like 'node' is not recognized, make sure Node.js is installed and its path is added to the environment variables.

Advanced Hello World Examples

1. Using Alert in a Browser

This example pops up a dialog box in the browser.


alert("Hello, World!");

Note: This only works in a browser context — not in Node.js.

2. Writing to the HTML Document

This method injects content into the webpage itself.


document.write("Hello, World on the Web Page!");

To use this, include it in a <script> tag inside an HTML file.


<!DOCTYPE html>
<html>
<head><title>JS Hello World</title></head>
<body>
  <script>
    document.write("Hello, World on the Web Page!");
  </script>
</body>
</html>

Key Concepts You Just Learned

Common Questions

Q: Can I run JavaScript without a browser?

Yes, by using Node.js or an online editor like Repl.it or JSFiddle.

Q: Is Node.js necessary to learn JavaScript?

No, but it's useful if you want to run JS outside the browser or build server-side applications.

Q: Why doesn't alert() work in Node.js?

Because alert() is part of the browser's window object and Node.js doesn't have a DOM.

Conclusion

Your first step into JavaScript is complete. You've learned not only how to write a basic Hello, World! but also how to execute it in different environments. From here, you can explore variables, functions, and beyond. The world of JS awaits — happy coding!

Module 1: Introduction to JavaScript❯

  1. 1What is JavaScript?
  2. 2Set Up JavaScript Environment
  3. 3JavaScript Hello World Program
  4. 4JavaScript in the Browser vs Node.js

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