JavaScript DOM Manipulation – Full Course for Beginners

What You Will Learn

• How to select elements in the DOM using various methods such as getElementById, getElementsByClassName, getElementsByTagName, querySelector, and querySelectorAll.
• How to manipulate the DOM by adding, removing, and modifying elements and their attributes.
• How to traverse the DOM tree using parent, child, and sibling relationships.

Key Concepts

The Document Object Model (DOM) is a tree-like structure that represents the HTML document, consisting of nodes such as elements, attributes, text content, and comments. The DOM object is a property of the window object, which is the global top-level object representing a tab in the browser. The document object has many properties and methods that can be used to manipulate the content, structure, and style of a project. Understanding the parent-child and sibling relationships between nodes is crucial for navigating and manipulating the DOM.

Code Examples

const title = document.getElementById('main-heading');
console.log(title);
// Logs the element with the id "main-heading" to the console.

const listItems = document.getElementsByClassName('list-items');
console.log(listItems);
// Logs an HTML collection of all elements with the class "list-items" to the console.

const container = document.querySelector('.container');
console.log(container);
// Logs the first element with the class "container" to the console.

Lesson Summary

In this lesson, we learned about the basics of the Document Object Model (DOM) and how to manipulate it using JavaScript. We started by understanding the structure of the DOM and how it represents the HTML document as a tree-like structure. We then learned about the different methods for selecting elements in the DOM, including getElementById, getElementsByClassName, getElementsByTagName, querySelector, and querySelectorAll. We also learned how to manipulate the DOM by adding, removing, and modifying elements and their attributes. Additionally, we covered how to traverse the DOM tree using parent, child, and sibling relationships. By understanding these concepts, we can start to build dynamic web pages that respond to user interactions.

Practice Exercise

Create a simple HTML page with a paragraph element and a button element. Use JavaScript to select the paragraph element and change its text content when the button is clicked.

What Is Next

In the next lesson, we will learn about event handling in JavaScript, which allows us to respond to user interactions such as clicks, hover, and keyboard input. We will learn how to attach event listeners to elements and how to handle events using callback functions.