Table of Contents
- What is the DOM?
- The DOM Tree
- Common DOM Methods and Properties
What is the DOM?
The Document Object Model, or DOM for short, is a programming interface that represents an HTML or XML document as a tree structure. Each node in the tree represents a part of the document, such as an element, attribute, or piece of text.
The DOM Tree
To better understand the DOM, it's important to know how it works. The DOM tree is a hierarchical structure that represents an HTML document as a tree of objects.
Each node in the tree represents a part of the document, such as an element, attribute, or piece of text. The root node is the top-level node, representing the entire document.
From there, the tree branches out into smaller nodes, each representing a child element or attribute of the parent node.
The DOM tree is created automatically when the browser loads an HTML document. You can use the developer tools in your browser to inspect the DOM tree of any web page.
For example, you can use the createElement method to create a new element, and then use the appendChild method to add it to the DOM tree.
// create a new element const newElement = document.createElement("p"); // add some text to the element newElement.textContent = "Hello, world!"; // add the element to the DOM tree document.body.appendChild(newElement);
Common DOM Methods and Properties
Returns the element with the specified ID.
Creates a new element with the specified tag name.
Adds a new child node to the end of the list of children of a node.
Removes a child node from the list of children of a node.
element.setAttribute(name, value) -
Sets the value of an attribute on the specified element.
Returns the value of the specified attribute on the element.
What is the difference between the DOM and HTML?
Yes, many programming languages have libraries or APIs that allow them to interact with the DOM, including Python, Ruby, and Java.
What is the difference between the innerHTML and textContent properties?
The innerHTML property returns the HTML content of an element, including any HTML tags, while the textContent property returns only the text content of an element, without any HTML tags.
Can the DOM be used to manipulate CSS styles?
Yes, you can use the DOM to add, remove, or modify CSS styles on an element using the style property.
Is the DOM the same in all web browsers?
No, there are some differences in how different browsers implement the DOM, particularly in older browsers. It's important to test your code in multiple browsers to ensure compatibility.