Summarize the methods of obtaining DOM elements in JavaScript
In work, we often need to obtain certain elements, and then modify the styles, contents, etc. of these elements. Do you know which methods can be used to obtain DOM elements? This article will tell you about the various methods of obtaining and finding elements in DOM in JavaScript, including getElementById(), getElementsByName(), etc. Friends who need it can refer to it. I hope it will be helpful to you.
1. getElementById()
Get the specified element through the specified id attribute value. If there is no element with the specified ID, null is returned; if there are multiple elements with the specified ID, undefined is returned. All browsers support the getElementById() method.
Writing method: document.getElementById(id)
Example: When the h1 tag is clicked, a prompt box will pop up to display the value in the h1 tag. The code is as follows:
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<h1 id="我是标题h">我是标题h1</h1>
</body>
<script type="text/javascript">
function myValue()
{
var a=document.getElementById("title")
alert(a.innerHTML)
}
</script>
</html>Rendering:
2. getElementsByClassName()
Get elements through the specified class attribute value . It returns a collection of elements with the specified class name, which is a collection of objects. getElementsByClassName can be called on any element, not just document. The element calling this method will be used as the root element of this search.
Browser support is as follows:
Writing method: document.getElementsByClassName(names)
##3. getElementsByTagName
Get elements through a specific tag name, which returns a collection with the specified tag name, which is a collection of objects. The getElementsByTagName() method returns elements in the order they appear in the document. All browsers support the getElementsByTagName() method. Writing method: document.getElementsByTagName(tagname)4. getElementsByName(name)
The getElementsByName method is similar to the getElementById method, the difference is the former Query the name attribute of the element, which queries the id attribute of the element. It returns a collection of objects with the specified name. All browsers support the getElementsByName() method. Writing method: document.getElementsByName(name)The above introduces the four methods of obtaining elements in JavaScript, including getElementById(id), getElementsByClassName(names), getElementsByTagName(tagname), getElementsByName( name), which method to use depends on your work needs. I hope this article will be helpful to you!The above is the detailed content of Summarize the methods of obtaining DOM elements in JavaScript. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
How to implement an online speech recognition system using WebSocket and JavaScript
Dec 17, 2023 pm 02:54 PM
How to use WebSocket and JavaScript to implement an online speech recognition system Introduction: With the continuous development of technology, speech recognition technology has become an important part of the field of artificial intelligence. The online speech recognition system based on WebSocket and JavaScript has the characteristics of low latency, real-time and cross-platform, and has become a widely used solution. This article will introduce how to use WebSocket and JavaScript to implement an online speech recognition system.
WebSocket and JavaScript: key technologies for implementing real-time monitoring systems
Dec 17, 2023 pm 05:30 PM
WebSocket and JavaScript: Key technologies for realizing real-time monitoring systems Introduction: With the rapid development of Internet technology, real-time monitoring systems have been widely used in various fields. One of the key technologies to achieve real-time monitoring is the combination of WebSocket and JavaScript. This article will introduce the application of WebSocket and JavaScript in real-time monitoring systems, give code examples, and explain their implementation principles in detail. 1. WebSocket technology
How to implement an online reservation system using WebSocket and JavaScript
Dec 17, 2023 am 09:39 AM
How to use WebSocket and JavaScript to implement an online reservation system. In today's digital era, more and more businesses and services need to provide online reservation functions. It is crucial to implement an efficient and real-time online reservation system. This article will introduce how to use WebSocket and JavaScript to implement an online reservation system, and provide specific code examples. 1. What is WebSocket? WebSocket is a full-duplex method on a single TCP connection.
How to use JavaScript and WebSocket to implement a real-time online ordering system
Dec 17, 2023 pm 12:09 PM
Introduction to how to use JavaScript and WebSocket to implement a real-time online ordering system: With the popularity of the Internet and the advancement of technology, more and more restaurants have begun to provide online ordering services. In order to implement a real-time online ordering system, we can use JavaScript and WebSocket technology. WebSocket is a full-duplex communication protocol based on the TCP protocol, which can realize real-time two-way communication between the client and the server. In the real-time online ordering system, when the user selects dishes and places an order
JavaScript and WebSocket: Building an efficient real-time weather forecasting system
Dec 17, 2023 pm 05:13 PM
JavaScript and WebSocket: Building an efficient real-time weather forecast system Introduction: Today, the accuracy of weather forecasts is of great significance to daily life and decision-making. As technology develops, we can provide more accurate and reliable weather forecasts by obtaining weather data in real time. In this article, we will learn how to use JavaScript and WebSocket technology to build an efficient real-time weather forecast system. This article will demonstrate the implementation process through specific code examples. We
Simple JavaScript Tutorial: How to Get HTTP Status Code
Jan 05, 2024 pm 06:08 PM
JavaScript tutorial: How to get HTTP status code, specific code examples are required. Preface: In web development, data interaction with the server is often involved. When communicating with the server, we often need to obtain the returned HTTP status code to determine whether the operation is successful, and perform corresponding processing based on different status codes. This article will teach you how to use JavaScript to obtain HTTP status codes and provide some practical code examples. Using XMLHttpRequest
How to get HTTP status code in JavaScript the easy way
Jan 05, 2024 pm 01:37 PM
Introduction to the method of obtaining HTTP status code in JavaScript: In front-end development, we often need to deal with the interaction with the back-end interface, and HTTP status code is a very important part of it. Understanding and obtaining HTTP status codes helps us better handle the data returned by the interface. This article will introduce how to use JavaScript to obtain HTTP status codes and provide specific code examples. 1. What is HTTP status code? HTTP status code means that when the browser initiates a request to the server, the service
How to use insertBefore in javascript
Nov 24, 2023 am 11:56 AM
Usage: In JavaScript, the insertBefore() method is used to insert a new node in the DOM tree. This method requires two parameters: the new node to be inserted and the reference node (that is, the node where the new node will be inserted).
