Introduction to JavaScript

What is JavaScript?

JavaScript (JS) is a high-level, interpreted programming language.Primarily used for adding interactivity and dynamic features to websites.

Ues of JS:

JavaScript is a versatile programming language used for web development, creating dynamic pages, form validation, and AJAX. It’s essential for web apps (React, Angular), backend (Node.js), mobile apps (React Native), games, desktop apps (Electron), data visualization, and real-time apps. It also powers machine learning, IoT, and browser extensions.

Use in Web Development:

Dynamic Content: JavaScript can change HTML content and CSS styles dynamically without reloading the page.

Interactivity: It responds to user actions like clicks, typing, or mouse movements.

Data Handling: It can fetch, display, and update data from external sources (e.g., APIs) in real-time.

Browser Control: JavaScript can control browser behavior such as navigation and pop-up windows.

Interaction with HTML and CSS:

HTML: Provides structure (headings, paragraphs, etc.), and JavaScript manipulates these elements through the DOM (Document Object Model).

CSS: JavaScript can modify CSS styles to change the appearance of elements, like colors, sizes, or visibility.

Key Features of JavaScript:

Event Handling: Handles events like clicks, key presses, and mouse movements.

Asynchronous Programming: Supports non-blocking operations using callbacks, Promises, and async/await.

Cross-Platform: Works on both client-side (browser) and server-side (Node.js) for full-stack development.

Basic Syntax:

Variables: let, const, and var are used to store data.

Functions: Group blocks of code to be reused.

Control Structures: Includes if-else statements, loops (for, while), etc.

Example: Changing Background Color

HTML: Defines a button.

Javascript: Listens for the button click event and changes the background color.

Change Background

<h1>This is a heading</h1>