class

全局属性 class 的值是一个以空格分隔的元素的类名（classes ）列表，它允许 CSS 和 Javascript 通过类选择器 (class selectors) 或DOM方法( document.getElementsByClassName)来选择和访问特定的元素。

尽管对class 的命名没有要求，但 web 开发者最好使用可以表达元素语义目的的名称，而不是描述元素展现的名称（即使一个元素是斜体，但是 class 的命名也不应该是 italics）。语义化命名即使在页面展现发生改变时仍能合乎逻辑。

规范

具体条目	标准	备注
HTML Living Standard class	Living Standard	No change from latest snapshot, HTML 5.1
HTML 5.1 class	Recommendation	Snapshot of HTML Living Standard, no change from HTML5
HTML5 class	Recommendation	Snapshot of HTML Living Standard. From HTML 4.01 Specification, class is now a true global attribute.
HTML 4.01 Specification class	Recommendation	Supported on all elements but `<base>`, `<basefont>`, `<head>`, `<html>`, `<meta>`, `<param>`, `<script>`, `<style>`, and `<title>`.

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`class`	Chrome Full support Yes	Edge Full support 12	Firefox Full support 32	IE Full support Yes	Opera Full support Yes	Safari Full support Yes	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support 32	Opera Android Full support Yes	Safari iOS Full support Yes	Samsung Internet Android Full support Yes