Javascript 多物体运动1

多物体运动

<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title></title>
  <style>
   div{
     50px;
    height: 30px;
    background: #444444;
    margin-top: 5px;

   }
  </style>
  <script>
   window.onload = function(){
    var obj = document.getElementsByTagName('div');

    for(var i=0;i<obj.length;i++){
     obj[i].onmouseover = function{
      startmove(this,500);
     };
     obj[i].onmouseout = function(){
      startmove(this,50);
     };
    }
   };

   var timer = null;
   function startmove(obj,target){
    var speed = (target-obj.offsetWidth)/6;
    speed = speed>0?Math.ceil(speed):Math.floor(speed);

    clearInterval(timer);
    timer = setInterval(function(){
     if(obj.offsetWidth == target){
      clearInterval(timer);
     }else{
      obj.style.width = obj.offsetWidth + speed +'px';
     }
    },30);
   }
  </script>
</head>
<body>
  <div></div>
  <div></div>
  <div></div>
</body>
</html>