Discover the essentials of HTML, CSS, and JavaScript to build interactive web applications through hands-on exercises, creating modules like an image carousel and a to-do list.

This course will teach you the fundamentals of creating web applications, from the basics of creating web pages with HTML, stylizing content with CSS, all the way to building interactivity into a page using JavaScript in the browser. 
Instead of watching tedious videos and wondering how to translate those videos into real code, you'll be practicing what you learn through interactive, test-based exercises within minutes. 

Along the way, you'll be able to produce functional modules, including an image carousel and a to-do list application. No prior knowledge is needed.

Learn HTML, CSS, and JavaScript from Scratch

The `id` and `class` attributes can be used to identify specific HTML elements across your HTML page. 

# The `id` attribute

The `id` attribute provides you with the ability to give any element a **unique identifier**. This identifier can later be used for things like applying specific styles with CSS or capturing input with some Javascript code.

```html
<h1 id="companyName">Educative.io</h1>
```

Some notes about `id` usage:
- An `id` value should only be used for a single element (you will get unexpected behavior if you use the same `id` value for multiple elements).
- An `id` value must not contain any whitespace. 
- A single element cannot have multiple `id` values.

# The `class` attribute

The `class` attribute is similar to the `id` attribute in that it is used to identify specific elements. The main distinctions are: 
- The same `class` value can be used across multiple elements.
- An element can have multiple `class` values, separated by whitespaces.

In the example below, the `id` and `class` attributes are used to apply CSS styles (*hidden*) to our HTML document. Take note of the main differences between the two attributes. 

Learn how to identify HTML elements on your page using ID and class attributes.

Semantic Web Page Layout with HTML

Stylizing HTML Content using CSS

Introduction to JavaScript, Basic Data Types and Operators

JavaScript Program Flow and Data Structures

Building Interactivity with DOM Manipulation

Create a To-do List Application using HTML, CSS, and JavaScript

Wrap Up

id and class Attributes