js 不同元素的同一属性运动

 1 <!DOCTYPE html>
 2 <html>
 3  <head>
 4   <meta charset="utf-8">
 5   <title></title>
 6   <style>
 7     div {
 8      50px;
 9     height: 50px;
10     background: red;
11     border: 1px solid red;
12     margin-top: 10px;
13    }
14   </style>
15  </head>
16  <body>
17   <div></div>
18   <div></div>
19   <div></div>
20   <script>
21    var odiv = document.getElementsByTagName('div');
22    //var timer = null;
23         var target = 300;
24        var target1 = 50   for (let i = 0; i < odiv.length; i++) {        odiv[i].onmouseover = function() {     clearInterval(odiv[i].timer);
25      odiv[i].timer = setInterval(function() {
26       var _cur = parseInt(getStyle(odiv[i], "width"));
27       var speed = Math.ceil((target - _cur) / 8);
28       odiv[i].style.width = _cur + speed + "px";
29       if (speed == 0) {
30        clearInterval(odiv[i].timer);
31       }
32      }, 20);
33     
34 }
35      odiv[i].onmouseout = function() {
36      clearInterval(odiv[i].timer);
37      odiv[i].timer = setInterval(function() {
38       var _cur = parseInt(getStyle(odiv[i],"width"));
39       var speed = Math.floor((target1 - _cur) / 8);
40       odiv[i].style.width = _cur + speed + "px";
41       if (speed == 0) {
42        clearInterval(odiv[i].timer);
43       }
44      }, 20);
45     }
46    }
47    //有一种方法既能取到行内样式又能取到非行内样式
48    function getStyle(obj,attr) {
49     if (window.getComputedStyle) {
50      return getComputedStyle(obj,null)[attr];
51     }
52     return obj.currentStyle[attr];
53    }
54   </script>
55  </body>
56 </html>