JavaScript DOM Explained: A Practical Beginner’s Tutorial
Introduction
JavaScript is a powerful programming language that enables the creation of dynamic and interactive web pages. The Document Object Model (DOM) is a critical concept in JavaScript.
The DOM is a tree-like structure that represents a web page’s HTML elements. Understanding the DOM is critical when altering and modifying web pages with JavaScript.
We will present a beginner’s guide to understanding the DOM in JavaScript in this article. We will go through the fundamentals of the DOM, such as its structure, how to access and alter DOM elements with JavaScript, and how to handle DOM events.
By the end of this article, you will have a strong understanding of the DOM and will be able to use it to develop.
What is the DOM?
The Document Object Model (DOM) is a web document programming interface. In other words, when you load a webpage in your browser, the DOM is constructed and the web page is represented as a collection of objects with which you may interact using JavaScript. These items comprise anything from HTML tags, attributes, and content to additional multimedia elements such as images and videos.
Why Understanding the DOM is Important?
Understanding the DOM is essential for creating dynamic and interactive web pages. JavaScript can be used to control the DOM and change the content and look of a webpage without reloading the entire page. You may utilise the DOM to construct responsive web designs, complex user interfaces, animations, and visual effects to make your web pages more engaging and user-friendly.
Understanding the Document Object Model
The Structure of the DOM
The DOM is organised in a tree-like hierarchical structure, with the HTML page serving as the root node. In the DOM structure, each HTML element, such as <p>, is represented as a node. These nodes have a variety of characteristics and methods that allow you to manipulate them effectively.
The Relationship Between HTML and the DOM
When you load an HTML page in a browser, the browser parses and interprets the HTML code and creates the corresponding DOM. The HTML tags form the backbone of the DOM, which means that any changes made to the DOM directly affect the presented HTML.
The Different Types of Nodes in the DOM
The DOM consists of different types of nodes, each representing different aspects of the web page. These nodes include the document node, element nodes, attribute nodes, text nodes, comment nodes, and more. Understanding these nodes and their properties is essential when working with the DOM.
Manipulating the DOM with JavaScript
Why Manipulating the DOM with JavaScript is Important?
Manipulating the DOM with JavaScript can make web pages more interactive and dynamic by allowing you to add, remove, or modify elements of the page or update content without reloading the entire page. This can lead to an improved user experience and help make your web pages more engaging.
The Benefits of Manipulating the DOM with JavaScript
Some benefits of manipulating the DOM with JavaScript include improved website performance, better user experience, and increased interactivity. With JavaScript, you can also add animations and transitions, build responsive layouts, and create dynamic user interfaces that enhance the user experience.
How to Manipulate the DOM with JavaScript
To manipulate the DOM with JavaScript, you need to use a variety of available methods and properties that allow you to add, remove, or modify nodes and their content. These include methods like createElement(), appendChild(), removeChild(), and more.
Accessing DOM Elements with JavaScript
The Different Ways to Access DOM Elements with JavaScript
There are several ways to access DOM elements with JavaScript. The most common ones include using selectors, such as:
getElementById()getElementsByClassName()querySelector()- and
querySelectorAll() - as well as accessing elements through the
documentobject.
Using Document Methods to Access DOM Elements with JavaScript
The document object has several methods you can use to access DOM elements. These include getElementById(), which returns an element with the specified ID, and getElementsByClassName(), which returns a collection of elements with the specified class name.
Using Element Methods to Access DOM Elements with JavaScript
In addition to the document object methods, you can also access DOM elements using various element methods, such as getElementsByTagName(), which returns a collection of elements with the specified tag name, and querySelector(), which returns the first element that matches a specified CSS selector.
Modifying DOM Elements with JavaScript
The Document Object Model (DOM) is a programming interface that allows you to modify the content, structure, and styles of an HTML document dynamically. Modifying the DOM with JavaScript is an essential skill for any web developer.
Here are some ways you can modify DOM elements with JavaScript:
Changing Element Content with JavaScript
To change the content of an element, you can use the innerHTML property. For example, to change the content of a paragraph element with an ID of “my-para”, you can use the following code:
const para = document.getElementById("my-para");
para.innerHTML = "New content";
Changing Element Attributes with JavaScript
To change the attributes of an element, such as its class, style, or ID, you can use the setAttribute method. For example, to change the class of an element with an ID of “my-div”, you can use the following code:
const div = document.getElementById("my-div");
div.setAttribute("class", "new-class");
Adding and Removing Elements with JavaScript
To add and remove elements, you can use the createElement, appendChild, and removeChild methods. For example, to add a new paragraph element to a div with an ID of “my-div”, you can use the following code:
let div = document.getElementById("my-div");
let newPara = document.createElement("p");
newPara.innerHTML = "New paragraph";
div.appendChild(newPara);
To remove an element, you can use the removeChild method. For example, to remove a paragraph element with an ID of “my-para”, you can use the following code:
let para = document.getElementById("my-para");
para.parentNode.removeChild(para);
Event Handling in the DOM with JavaScript
What are Events in the DOM?
Events are actions or occurrences that happen in the browser, such as clicking a button or submitting a form. Event handling is the process of responding to these events in JavaScript.
How to Handle Events in the DOM with JavaScript
To handle events in JavaScript, you can use the addEventListener method. For example, to handle a click event on a button element with an ID of “my-button”, you can use the following code:
let button = document.getElementById("my-button");
button.addEventListener("click", function() {
alert("Button clicked");
});
The Different Types of Events in the DOM
There are many types of events in the DOM, including click, submit, keydown, and mouseover. You can find a full list of DOM events in the MDN web docs.
Common DOM Methods and Properties in JavaScript
The Most Commonly Used DOM Methods in JavaScript
Some of the most commonly used DOM methods in JavaScript include getElementById, createElement, appendChild, setAttribute, and innerHTML.
These methods are frequently used to access, manipulate, and interact with DOM elements in JavaScript.
- The most commonly used DOM methods in JavaScript include:
-
getElementById(): Retrieves an element from the DOM based on its unique ID. -
getElementsByTagName(): Retrieves a collection of elements based on their tag name. -
getElementsByClassName(): Retrieves a collection of elements based on their class name. -
querySelector(): Retrieves the first element that matches a specific CSS selector. -
querySelectorAll(): Retrieves all elements that match a specific CSS selector. -
createElement(): Creates a new element. -
appendChild(): Appends a new child element to an existing element. -
removeChild(): Removes a child element from an existing element. -
setAttribute(): Sets the value of a specific attribute of an element. -
addEventListener(): Adds an event listener to an element to handle specific events.
The Most Commonly Used DOM Properties in JavaScript
InnerHTML, style, className, tagName, and parentNode just a few of the most frequently used DOM properties in JavaScript. Understanding these methods and properties is critical for changing and interacting with the DOM in JavaScript.
Here is a list of properties that are frequently used to access and manipulate various aspects of DOM elements in JavaScript:
- The most commonly used DOM properties in JavaScript include:
-
innerHTML: Represents the HTML content within an element. -
textContent: Represents the text content within an element. -
style: Provides access to the inline styles of an element. -
className: Represents the class attribute of an element. -
id: Represents the ID attribute of an element. -
tagName: Represents the tag name of an element. -
parentNode: Represents the parent node of an element. -
childNodes: Represents a collection of child nodes of an element. -
getAttribute(): Retrieves the value of a specific attribute of an element. -
setAttribute(): Sets the value of a specific attribute of an element.
The Document Object Model is a fundamental concept in JavaScript that allows us to access, manipulate, and alter HTML elements on web pages.
Conclusion
Finally, understanding the Document Object Model (DOM) is essential for developing engaging and dynamic web pages with JavaScript.
The DOM is a tree-like structure that represents a web page’s HTML elements and allows us to manipulate and edit them.
You can construct responsive web designs, complicated user interfaces, and add animations and visual effects by learning the DOM.
This beginner’s guide has covered the fundamentals of the DOM, such as its structure, accessing and manipulating DOM elements, and handling events.
You may become adept in interacting with the DOM and creating more interactive web experiences with practice.
Best wishes on your adventure into the wonderful world of JavaScript!
Disclaimer: “This article was created with the help of AI”.
Further reading
Looking to dive deeper into the topic of Document Object Model? Then check out – Document Object Model (DOM) – Web APIs | MDN
See also
What exactly is JavaScript?
Why JavaScript is a Great Programming Language for Beginners
What is the Syntax of JavaScript?
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Top comments (2)
Great post! Well explained
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