JavaScript实现简单表格排序功能

<!DOCTYPE>
<html>
<head>
  <meta http-equiv="Content-type" content="text/html" charset="utf-8">
  <title>sort table</title>
  <style>
    *{
      margin:0px;
      padding:0px;
    }
    body{
      background:#ccc;
    }
    table{
      width:350px;
      margin:0 auto;
      background-color:#eee;
    }
    table th{
      cursor:hand;
      padding:5px 0;
      background-color:#999;
    }
    table td{
      background-color:#fff;
      font-size:16px;
      font-weight:normal;
      text-align:center;
      line-height:30px;
    }
  </style>
  <script language="javascript">
    function sortCells(type){
      var tbs=document.getElementsByTagName("table")[0];
      var arr=[];
      var arr2=[];
      for(var i=1;i<tbs.rows.length;i++){
        var text=tbs.rows[i].cells[type].innerText;
        arr.push(text);
        arr2[text]=i;
      }
      if(type==0){
        arr.sort(function(a,b){return a-b});
      }else{
        arr.sort();
      }
      var temp="";
      for(var j=1;j<tbs.rows.length;j++){
        temp=tbs.rows[j].cells[0].innerText;
        tbs.rows[j].cells[0].innerText=tbs.rows[arr2[arr[j-1]]].cells[0].innerText;
        tbs.rows[arr2[arr[j-1]]].cells[0].innerText=temp;
        temp=tbs.rows[j].cells[1].innerText;
        tbs.rows[j].cells[1].innerText=tbs.rows[arr2[arr[j-1]]].cells[1].innerText;
        tbs.rows[arr2[arr[j-1]]].cells[1].innerText=temp;
        temp=tbs.rows[j].cells[2].innerText;
        tbs.rows[j].cells[2].innerText=tbs.rows[arr2[arr[j-1]]].cells[2].innerText;
        tbs.rows[arr2[arr[j-1]]].cells[2].innerText=temp;
//        console.log(arr2);
        for(var i=1;i<tbs.rows.length;i++){
          var text=tbs.rows[i].cells[type].innerText;
          arr2[text]=i;
        }
      }
    }
  </script>
</head>
<body>
<center>sort table</center>
<table border="0">
  <tr>
    <th onclick="sortCells(0);">序号</th>
    <th onclick="sortCells(1);">姓名</th>
    <th onclick="sortCells(2);">日期</th>
  </tr>
  <tr>
    <td>2</td>
    <td>BB</td>
    <td>2015-09-12</td>
  </tr>
   <tr>
    <td>3</td>
    <td>CC</td>
    <td>2015-07-12</td>
  </tr>
   <tr>
    <td>1</td>
    <td>AA</td>
    <td>2015-09-11</td>
  </tr>
   <tr>
    <td>4</td>
    <td>DD</td>
    <td>2015-06-12</td>
  </tr>
</table>
</body>
</html>