<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="utf-8">
<title>Document</title>
<style>
.box{
width: 100px;
height: 100px;
background-color: yellowgreen;
padding: 20px;
}
</style>
</head>
<body>
<div id="box" class="box"></div>
<script>
var oDiv = document.getElementById('box');
oDiv.onclick = function (){
//this.style.width 获取的是行间样式(设定的也是行间样式)
//alert(this.style.width);
// 给 ie浏览器使用的 obj.currentStyle[你的属性]
//alert(oDiv.currentStyle['width']);
// chrome 、firefox、ie9+
// alert(getComputedStyle(谁,false)[attr]);
alert(getComputedStyle(oDiv,false)['width']);
}
</script>
</body>
</html>