We know that if you want to operate CSS in JS, the most important thing is to obtain the style. Here is an article about the most common methods of obtaining styles in JS for your reference.
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
div{
color:yellow;
}
</style>
</head>
<body>
<div style="width:100px;height:100px;background-color:red">This is div</div>
</body>
</html>Get it by using the element.style property
<script>
var div = document.getElementsByTagName("div")[0];
console.log(div.style.color); //""
console.log(div.style.backgroundColor); //red
</script>The element.style property can only get the inline style, not the style in the
Since element.style is an attribute of the element, we can reassign the attribute to rewrite the display of the element.
<script>
var div = document.getElementsByTagName("div")[0];
div.style['background-color'] = "green";
console.log(div.style.backgroundColor); //green
</script>2. Get the style through getComputedStyle and currentStyle
The usage environment of getComputedStyle is chrome/safari/firefox IE 9,10,11
<script>
var div = document.getElementsByTagName("div")[0];
var styleObj = window.getComputedStyle(div,null);
console.log(styleObj.backgroundColor); //red
console.log(styleObj.color); //yellow
</script>currentStyle can be used in IE It is perfectly supported, chrome does not support it, and ff does not support it
<script>
var div = document.getElementsByTagName("div")[0];
var styleObj = div.currentStyle;
console.log(styleObj.backgroundColor); //red
console.log(styleObj.color); //yellow
</script>3. The difference between ele.style and getComputedStyle or currentStyle
3.1 ele.style is read and write, while getComputedStyle and currentStyle are only Read
3.2 ele.style can only get the CSS style set in the inline style attribute, while getComputedStyle and currentStyle can also get other default values
3.3 ele.style gets the style attribute The style in is not necessarily the final style, while the other two get the final CSS style of the element
4. How to get style compatibility
<script>
//获取非行间样式(style标签里的样式或者link css文件里的样式)，obj是元素，attr是样式名
function getStyle(obj,attr){
//针对IE
if(obj.currentStyle){
return obj.currentStyle[attr]; //由于函数传过来的attr是字符串，所以得用[]来取值
}else{
//针对非IE
return window.getComputedStyle(obj,false)[attr];
}
}
function css(obj,attr,value){
if(arguments.length == 2){
return getStyle(obj,attr);
}else{
obj.style[attr] = value;
}
}
</script>
.window.getComputedStyle(ele[,pseudoElt]);If the second parameter is null or If omitted, the CSSStyleDeclaration object of ele will be obtained.
If it is a pseudo-class, the CSSStyleDeclaration object of the pseudo-class will be obtained.
<style>
div{
width:200px;
height:200px;
background-color:#FC9;
font-size:20px;
text-align:center;
}
div:after{
content:"This is after";
display:block;
width:100px;
height:100px;
background-color:#F93;
margin:0 auto;
line-height:50px;
}
</style>
<body>
<div id='myDiv'>
This is div
</div>
<input id='btn' type="button" value='getStyle'/>
<script>
var btn = document.querySelector('#btn');
btn.onclick = function(){
var div = document.querySelector('#myDiv');
var styleObj = window.getComputedStyle(div,'after');
console.log(styleObj['width']);
}
</script>
</body>getPropertyValue acquisition The specified property value in the CSSStyleDeclaration object
<script>
var div = document.getElementsByTagName("div")[0];
var styleObj = window.getComputedStyle(div,null);
console.log(styleObj.getPropertyValue("background-color"));
</script>
getPropertyValue(propertyName);中的propertyName不能是驼峰式表示
obj.currentStyle['margin-left'] 有效
obj.currentStyle['marginLeft'] 有效
window.getComputedStyle(obj,null)['margin-left'] 有效
window.getComputedStyle(obj,null)['marginLeft'] 有效
window.getComputedStyle(obj,null).getPropertyValue('margin-left') 有效
window.getComputedStyle(obj,null).getPropertyValue('marginLeft') 无效
obj.currentStyle.width 有效
obj.currentStyle.background-color 无效
obj.currentStyle.backgroundColor 有效
window.getComputedStyle(obj,null).width 有效
window.getComputedStyle(obj,null).background-color 无效
window.getComputedStyle(obj,null).backgroundColor 有效To sum up, the property with "-" cannot be directly clicked, so there is the getPropertyValue method to handle it, but you can use [] to Replaces getPropertyValue
7.defaultView
In many online demo codes, getComputedStyle is called through the document.defaultView object. In most cases, this is not needed because it can be called directly through the window object. But there is one situation where you must use defaultView, which is to access the style (iframe) in the subframe on firefox3.6
I believe you have mastered the method after reading these cases, please pay attention to php for more exciting information Other related articles on the Chinese website!
Related reading:
How to hide divs in HTML using CSS
How to use Vue+CSS3 to create interactive effects
How to solve the bug that emoji expressions cannot be sent on the front end
The above is the detailed content of Common ways to get styles in Js. For more information, please follow other related articles on the PHP Chinese website!
JavaScript in Action: Real-World Examples and ProjectsApr 19, 2025 am 12:13 AMJavaScript's application in the real world includes front-end and back-end development. 1) Display front-end applications by building a TODO list application, involving DOM operations and event processing. 2) Build RESTfulAPI through Node.js and Express to demonstrate back-end applications.
JavaScript and the Web: Core Functionality and Use CasesApr 18, 2025 am 12:19 AMThe main uses of JavaScript in web development include client interaction, form verification and asynchronous communication. 1) Dynamic content update and user interaction through DOM operations; 2) Client verification is carried out before the user submits data to improve the user experience; 3) Refreshless communication with the server is achieved through AJAX technology.
Understanding the JavaScript Engine: Implementation DetailsApr 17, 2025 am 12:05 AMUnderstanding how JavaScript engine works internally is important to developers because it helps write more efficient code and understand performance bottlenecks and optimization strategies. 1) The engine's workflow includes three stages: parsing, compiling and execution; 2) During the execution process, the engine will perform dynamic optimization, such as inline cache and hidden classes; 3) Best practices include avoiding global variables, optimizing loops, using const and lets, and avoiding excessive use of closures.
Python vs. JavaScript: The Learning Curve and Ease of UseApr 16, 2025 am 12:12 AMPython is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.
Python vs. JavaScript: Community, Libraries, and ResourcesApr 15, 2025 am 12:16 AMPython and JavaScript have their own advantages and disadvantages in terms of community, libraries and resources. 1) The Python community is friendly and suitable for beginners, but the front-end development resources are not as rich as JavaScript. 2) Python is powerful in data science and machine learning libraries, while JavaScript is better in front-end development libraries and frameworks. 3) Both have rich learning resources, but Python is suitable for starting with official documents, while JavaScript is better with MDNWebDocs. The choice should be based on project needs and personal interests.
From C/C to JavaScript: How It All WorksApr 14, 2025 am 12:05 AMThe shift from C/C to JavaScript requires adapting to dynamic typing, garbage collection and asynchronous programming. 1) C/C is a statically typed language that requires manual memory management, while JavaScript is dynamically typed and garbage collection is automatically processed. 2) C/C needs to be compiled into machine code, while JavaScript is an interpreted language. 3) JavaScript introduces concepts such as closures, prototype chains and Promise, which enhances flexibility and asynchronous programming capabilities.
JavaScript Engines: Comparing ImplementationsApr 13, 2025 am 12:05 AMDifferent JavaScript engines have different effects when parsing and executing JavaScript code, because the implementation principles and optimization strategies of each engine differ. 1. Lexical analysis: convert source code into lexical unit. 2. Grammar analysis: Generate an abstract syntax tree. 3. Optimization and compilation: Generate machine code through the JIT compiler. 4. Execute: Run the machine code. V8 engine optimizes through instant compilation and hidden class, SpiderMonkey uses a type inference system, resulting in different performance performance on the same code.
Beyond the Browser: JavaScript in the Real WorldApr 12, 2025 am 12:06 AMJavaScript's applications in the real world include server-side programming, mobile application development and Internet of Things control: 1. Server-side programming is realized through Node.js, suitable for high concurrent request processing. 2. Mobile application development is carried out through ReactNative and supports cross-platform deployment. 3. Used for IoT device control through Johnny-Five library, suitable for hardware interaction.
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
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
SublimeText3 Linux new version
SublimeText3 Linux latest version
Dreamweaver Mac version
Visual web development tools
ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment
SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.
SublimeText3 Mac version
God-level code editing software (SublimeText3)
