<!DOCTYPE html>

 <html lang="en">

 <head>

     <meta charset="UTF-8">

     <meta name="viewport" content="width=device-width, initial-scale=1.0">

     <meta http-equiv="X-UA-Compatible" content="ie=edge">

     <title>获取css样式</title>

 </head>

 <style>

     #box{

         position: absolute;

         left: 50%;

         top: 100px;

         background-color: #fff000;

         color: blueviolet;

         font-size: 2em;

         font-weight: bolder;

         text-align: center;

         width: 300px;

         height: 100px;

         line-height: 100px;

         font-style: italic;

     }

 </style>

 <body>

     <div id="box">ProsperLee</div>

     <pre>

         #box{

             position: absolute;

             left: 50%;

             top: 100px;

             background-color: #fff000;

             color: blueviolet;

             font-size: 2em;

             font-weight: bolder;

             text-align: center;

             width: 300px;

             height: 100px;

             line-height: 100px;

             font-style: italic;

         }

     </pre>

     <script>

         /**

          * 获取css样式

          * ele 元素

          * prop 属性名

          **/

         function getStyle(ele, prop) {

             if (window.getComputedStyle) {

                 return window.getComputedStyle(ele, null)[prop];

             } else {

                 return ele.currentStyle[prop];

             }

         }

         var el = document.getElementById('box');

         console.log('position：' + getStyle(el,'position')); // absolute

         console.log('left：' + getStyle(el,'left')); // 488.5px

         console.log('font-size：' + getStyle(el,'font-size')); // 32px

         console.log('font-style：' + getStyle(el,'font-style')); // italic

         console.log('max-width：' + getStyle(el,'max-width')); // none

         console.log('bottom：' + getStyle(el,'bottom')); // 532px

     </script>

 </body>

 </html>