HTML、CSS及JavaScript ： JavaScript征服Style的五种武器_html/css

Home

Web Front-end

HTML Tutorial

HTML、CSS及JavaScript ： JavaScript征服Style的五种武器_html/css_WEB-ITnose

WBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWB

Jun 24, 2016 am 11:15 AM

在HTML的世界里，对于一个元素来说，看的主要不是气质，而是它的Style，因为Style决定了颜值。俗话说，JavaScript与Style，得其一者得天下。但是，Style永远无法改变JavaScript，JavaScript却可以征服Style。因为JavaScript有五种武器，所以可以对Style为所欲为，既可远观，亦可亵玩。

第一种武器是 className，在JavaScript，得到一个元素的 className就是得到了这个元素的 class属性的值。Show Code：

<div id="box" class="one two"/><script>  var box = document.getElementById("box")  alert(box.className)  box.className += ' three'</script>

上面的代码拿到 box的 class，然后又给它添加了一个 three。如果想去掉某个 class，只要通过字符串操作去掉，然后重新给 className赋值就可以了。

第二种武器是 style，确切地说，这是个武器包，你几乎可以用它修改所有 style。比如说你执行了 box.style.width='100px'，就相当于在 box上添加了一个 style="width:100px"。

对于那些由多个单词组成的style值，就是 background-color、 marigin-top之类的，要把横线去掉，然后单词的首字母大写。对，改成像 backgroundColor、 mariginTop这样。像 -moz-border-radius这种，也是把 -去掉，然后后面的字母换成大写，就是改成 MozBorderRadius。

因为style属性优先与css，所以你可以用style覆盖掉css中设置的样式，也可以把它设成空字符串还原：

var box = document.getElementById("box")box.style.width='100px'box.style.width=''

上面的代码最终会保持box的 width不变。

第三种武器是 cssText，好吧，实际上它也是style中的一个属性。但因为它很强大，所以我们特意提高了它的地位。用 style.cssText可以获取和设置完整的style内容。

<div>Button</div><script>  var div = document.body.children[0]  div.style.cssText='color: red !important; \    background-color: yellow; \    width: 100px; \    text-align: center; \    blabla: 5; \  '  alert(div.style.cssText)</script>

浏览器会对 cssText进行解析，然后把解析结果应用到元素上去。上面代码中那个不认识blabla就直接忽略掉了，不会报错，所以要注意typo。

并且如果你想加 !important，只能用 cssText。

接下来要出场的，是真正重量级的两种武器，或者说一又十分之一种武器。一种是标准的 getComputedStyle，另外一种是它的十分之一变种，自恋的M$IE专为自己打造的 currentStyle（哦，据说它的市场份额只有十分之一了嘛）。

在真实的页面中，我们很少见到在元素的 style属性中设置的样式，所以用 style几乎读取不到任何元素的Style。比如下面这个例子：

<style>  body { margin: 10px }</style><body>  <script>    alert(document.body.style.marginTop)  </script> </body>

是得不到任何值的。

这种需求只能靠 window.getComputedStyle来解决，这个方法是 DOM Level 2的标准方法，所有浏览器（除了IE

所以要获取上面那个例子中的marginTop，以及所有在浏览器给元素应用了style和样式表之后的Style，都可以像下面这样：

<style>  body { margin: 10px }</style><body>  <script>    var computedStyle = getComputedStyle(document.body, null)    alert(computedStyle.marginTop)  </script></body>

至于IE 9之前的浏览器，就得用 currentStyle读取了。或者像这样：

<style>  body { margin: 10% }</style><body><script>    if (window.getComputedStyle) {      var computedStyle = getComputedStyle(document.body, null)    } else {      computedStyle = document.body.currentStyle    }    alert(computedStyle.marginTop)  </script></body>

好了，上面就是JavaScript征服Style的五种武器。不过我是只用前面四种武器的，既然用户到现在还用IE

声明：本文参考(抄袭)了 Styles and classes, getComputedStyle

Statement

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

The Future of HTML, CSS, and JavaScript: Web Development TrendsApr 19, 2025 am 12:02 AM

The future trends of HTML are semantics and web components, the future trends of CSS are CSS-in-JS and CSSHoudini, and the future trends of JavaScript are WebAssembly and Serverless. 1. HTML semantics improve accessibility and SEO effects, and Web components improve development efficiency, but attention should be paid to browser compatibility. 2. CSS-in-JS enhances style management flexibility but may increase file size. CSSHoudini allows direct operation of CSS rendering. 3.WebAssembly optimizes browser application performance but has a steep learning curve, and Serverless simplifies development but requires optimization of cold start problems.

HTML: The Structure, CSS: The Style, JavaScript: The BehaviorApr 18, 2025 am 12:09 AM

The roles of HTML, CSS and JavaScript in web development are: 1. HTML defines the web page structure, 2. CSS controls the web page style, and 3. JavaScript adds dynamic behavior. Together, they build the framework, aesthetics and interactivity of modern websites.

The Future of HTML: Evolution and Trends in Web DesignApr 17, 2025 am 12:12 AM

The future of HTML is full of infinite possibilities. 1) New features and standards will include more semantic tags and the popularity of WebComponents. 2) The web design trend will continue to develop towards responsive and accessible design. 3) Performance optimization will improve the user experience through responsive image loading and lazy loading technologies.

HTML vs. CSS vs. JavaScript: A Comparative OverviewApr 16, 2025 am 12:04 AM

The roles of HTML, CSS and JavaScript in web development are: HTML is responsible for content structure, CSS is responsible for style, and JavaScript is responsible for dynamic behavior. 1. HTML defines the web page structure and content through tags to ensure semantics. 2. CSS controls the web page style through selectors and attributes to make it beautiful and easy to read. 3. JavaScript controls web page behavior through scripts to achieve dynamic and interactive functions.

HTML: Is It a Programming Language or Something Else?Apr 15, 2025 am 12:13 AM

HTMLisnotaprogramminglanguage;itisamarkuplanguage.1)HTMLstructuresandformatswebcontentusingtags.2)ItworkswithCSSforstylingandJavaScriptforinteractivity,enhancingwebdevelopment.

HTML: Building the Structure of Web PagesApr 14, 2025 am 12:14 AM

HTML is the cornerstone of building web page structure. 1. HTML defines the content structure and semantics, and uses, etc. tags. 2. Provide semantic markers, such as, etc., to improve SEO effect. 3. To realize user interaction through tags, pay attention to form verification. 4. Use advanced elements such as, combined with JavaScript to achieve dynamic effects. 5. Common errors include unclosed labels and unquoted attribute values, and verification tools are required. 6. Optimization strategies include reducing HTTP requests, compressing HTML, using semantic tags, etc.

From Text to Websites: The Power of HTMLApr 13, 2025 am 12:07 AM

HTML is a language used to build web pages, defining web page structure and content through tags and attributes. 1) HTML organizes document structure through tags, such as,. 2) The browser parses HTML to build the DOM and renders the web page. 3) New features of HTML5, such as, enhance multimedia functions. 4) Common errors include unclosed labels and unquoted attribute values. 5) Optimization suggestions include using semantic tags and reducing file size.

Understanding HTML, CSS, and JavaScript: A Beginner's GuideApr 12, 2025 am 12:02 AM

WebdevelopmentreliesonHTML,CSS,andJavaScript:1)HTMLstructurescontent,2)CSSstylesit,and3)JavaScriptaddsinteractivity,formingthebasisofmodernwebexperiences.

See all articles