<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>>js获取盒模型宽和高的方法</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        #div1{
            width: 100px;
            height: 100px;
            padding: 10px;
            border:10px solid #000000;
            background: #ffff00;
        }
        #div2{
            width: 100px;
            height: 100px;
            padding: 10px;
            border:10px solid #0000ff;
            background: #ff0000;
            box-sizing: border-box;
        }
    </style>
</head>
<body>
  <p>dom.style.width/height;</p>        
 <div id="div1" style="width: 100px">哟哟哟</div>        
 <div id="div2">嘿嘿嘿</div>       
 <script>            
 var oDiv1 = document.getElementById("div1");           
 console.log(oDiv1.style.width ) ;        
 </script>
 </body>
</html>
效果图:

缺点:通过这种方式,只能获取行内样式,不能获取内嵌的样式和外链的样式。
⑵这种方法获取的是浏览器渲染以后的元素的宽和高,这种写法兼容性更好一些。
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>>js获取盒模型宽和高的方法</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        #div1{
            width: 100px;
            height: 100px;
            padding: 10px;
            border:10px solid #000000;
            background: #ffff00;
        }
        #div2{
            width: 100px;
            height: 100px;
            padding: 10px;
            border:10px solid #0000ff;
            background: #ff0000;
            box-sizing: border-box;
        }
    </style>
</head>
<body>
<p>window.getComputedStyle(element).width/height;</p>        
<div id="div1" >111</div>
<div id="div2">222</div>
<script>
var oDiv1 = document.getElementById("div1");
console.log( window.getComputedStyle(oDiv1).width ) ;
</script>
</body>
</html>
效果图:

㈢方式三(IE独有的)
⑴dom.currentStyle.width/height
⑵这种方法获取的是浏览器渲染以后的元素的宽和高,无论是用何种方式引入的css样式都可以,但只有IE浏览器支持这种写法。
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>>js获取盒模型宽和高的方法</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        #div1{
            width: 100px;
            height: 100px;
            padding: 10px;
            border:10px solid #000000;
            background: #ffff00;
        }
        #div2{
            width: 100px;
            height: 100px;
            padding: 10px;
            border:10px solid #0000ff;
            background: #ff0000;
            box-sizing: border-box;
        }
    </style>
</head>
<body>
<p>dom.currentStyle.width/height;</p>        
<div id="div1" >哟哟哟</div>
<div id="div2">呵呵呵</div>
<script>
var oDiv1 = document.getElementById("div1");
console.log( oDiv1.currentStyle.width);
</script>
</body>
</html>
效果图:

⑴dom.getBoundingClientRect().width/height
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>>js获取盒模型宽和高的方法</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        #div1{
            width: 100px;
            height: 100px;
            padding: 10px;
            border:10px solid #000000;
            background: #ffff00;
        }
        #div2{
            width: 100px;
            height: 100px;
            padding: 10px;
            border:10px solid #0000ff;
            background: #ff0000;
            box-sizing: border-box;
        }
    </style>
</head>
<body>
<p>dom.getBoundingClientRect().width/height;</p>        
<div id="div1" >111</div>
<div id="div2">222</div>
<script>
var oDiv1 = document.getElementById("div1");
console.log(oDiv1.getBoundingClientRect().width);
</script>
</body>
</html>
效果图:

原文:https://www.cnblogs.com/shihaiying/p/11600229.html