CSSStyleDeclaration.length
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2015.
这是一个只读的属性，它返回一个指定元素声明过的样式个数
语法
var num = styles.length;
值
指定元素上明确声明过的样式属性个数。
示例
获取下面 HTML 元素明确设置过的属性个数：
html
<div
id="div1"
style="margin: 0 10px; background-color: #CA1; font-family: monospace"></div>
JavaScript 代码：
var myDiv = document.getElementById('div1'); var divStyle = myDiv.style; var len = divStyle.length; // 6
规范
| Specification |
|---|
| CSS Object Model (CSSOM) # dom-cssstyledeclaration-length |
浏览器兼容性
BCD tables only load in the browser