What is JavaScript? JavaScript Development Environment JavaScript Variables and Data Types Operators in JavaScript Control Structures in JavaScript JavaScript Functions JavaScript Arrays Complete Guide JavaScript Objects and JSON DOM Manipulation Basics Event Handling in JavaScript JavaScript ES6 Features Overview JavaScript Promises and Async Async Await in JavaScript Fetch API and AJAX JavaScript Modules ES6 Local Storage and Session Storage JavaScript Error Handling JavaScript Closures Explained JavaScript Prototypes and Inheritance ES6 Classes in JavaScript JavaScript Template Literals Destructuring Assignment ES6 Spread Operator in JavaScript JavaScript Map and Set JavaScript Symbol Data Type Optional Chaining and Nullish JavaScript Generators JavaScript Proxy and Reflect Web APIs Canvas SVG JavaScript Web Workers

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What is JavaScript?

April 5, 2026

What is JavaScript?

JavaScript is a high-level, interpreted programming language primarily used for web development. It adds interactivity to websites through client-side scripting.

First JavaScript Program

<!DOCTYPE html>
<html>
<head>
    <title>My First JS</title>
</head>
<body>
    <h1></h1>
    <script>
        console.log("Hello, World!");
        document.querySelector("h1").textContent = "Hello JavaScript!";
    </script>
</body>
</html>

Key Points

JavaScript runs in browser (client-side) or Node.js (server-side).
<code><script></code> tags or external .js files.
console.log() for debugging.
Manipulates DOM via document object.

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