js盒模型

 1 <!DOCTYPE html>
 2 <html lang="zh">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title>js盒模型</title>
 6 
 7     <style type="text/css">
 8         .sup {
 9             width: 200px;
10             height: 200px;
11             padding: 30px;
12             border: 5px solid black;
13             background-color: orange;
14             margin: 20px;
15             position: relative;
16         }
17 
18         .sub {
19             width: 100px;
20             height: 100px;
21             padding: 20px;
22             border: 5px solid black;
23             background-color: red;
24             position: absolute;
25             top: 0;
26             left: 20px;
27         }
28     </style>
29 </head>
30 <body>
31     <div class="sup">
32         <div class="sub"></div>
33     </div>
34 </body>
35 <script type="text/javascript">
36     var sup = document.querySelector('.sup');
37     // 盒子content的width
38     var width = parseInt(getComputedStyle(sup, null).width);
39     console.log(width);
40 
41     // 盒子padding+width => 子级的可活动范围
42     var p_width = sup.clientWidth;
43     console.log(p_width);
44 
45     // 盒子border+padding+width => 可视区域
46     var b_p_width = sup.offsetWidth;
47     console.log(b_p_width);
48 
49     // 盒子距离定位父级的top,left
50     var sup_top = sup.offsetTop;
51     var sup_left = sup.offsetLeft;
52     console.log(sup_top);
53     console.log(sup_left);
54 
55 
56     var sub = document.querySelector('.sub');
57     // 父级定位(relative)后,子级活动区域为父级的client(padding+width)区域
58     var sub_top = sub.offsetTop;
59     var sub_left = sub.offsetLeft;
60     console.log(sub_top);
61     console.log(sub_left);
62 
63 </script>
64 </html>