What object in JavaScript is used for

What objects in JavaScript are used to operate DOM

DOM (Document Object Model) is a programming interface for HTML and XML documents, which allows developers to access the content of HTML or XML documents in an object-oriented manner. , structure and attributes, so that the appearance and behavior of web pages can be dynamically changed.

As a client-side scripting language, JavaScript can directly operate the DOM, such as modifying text content, adding or deleting elements, modifying styles, etc. Below we introduce some important objects used to manipulate the DOM in JavaScript.

1. document object

The document object represents the entire HTML or XML document, which is also the root node of the DOM tree. We can obtain various elements in the web page through the document object and operate on them. For example, you can use the document.getElementById() method to obtain an element object by its ID, and then use the properties or methods of the element object to modify the content or style of the element.

2. Element object

The Element object represents an element in an HTML or XML document and is the base class for all HTML element objects. Through the properties and methods of the Element object, you can obtain and modify various characteristics of the element, such as the element's content, style, size, position, etc. For example, you can use the element.textContent property to get or set the text content of an element, and the element.style property to modify the element's style.

3. NodeList object

The NodeList object represents the list of nodes in the document. It is a collection of Node objects. NodeList objects can be obtained by accessing the DOM tree, such as through the document.getElementsByTagName() method or the element.childNodes property. Use the traversal methods of the NodeList object (such as the forEach() method or the for loop) to traverse the node list and perform operations, such as modifying the text content or style of the node.

4. Text node

Text node represents text content, which is a child node of the Element node. Through the properties and methods of the Text node, the content, length, position, etc. of the text node can be obtained and modified. For example, you can use the textNode.textContent property to get or set the text content of a text node.

5. Event object

Event object represents an event, which contains various information about the event, such as the element where the event occurred, event type, mouse coordinates, etc. You can use the Event object to handle various events in JavaScript, such as clicks, double-clicks, mouse movements, keyboard keys, etc. By adding event listeners, JavaScript code can be executed when an event occurs on an element, thereby achieving a dynamic and responsive web page.

In JavaScript, operating DOM is a very important part. It allows us to achieve dynamic interactive effects, thereby improving user experience and website usability. Proficiency in DOM manipulation objects and methods in JavaScript is very necessary for developing high-quality web applications.

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