JavaScript与CSS实现鼠标悬停表格高亮效果

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>高亮的表格</title>
<meta http-equiv="content-type"
 content="text/html; charset=iso-8859-1" />
<style>
p, td, th {
  font: 0.8em Arial, Helvetica, sans-serif;
}
.datatable {
  border: 1px solid #D6DDE6;
  border-collapse: collapse;
  width: 80%;
}
.datatable td {
  border: 1px solid #D6DDE6;  
  padding: 4px;
}
.datatable th {
  border: 1px solid #828282;
  background-color: #BCBCBC;
  font-weight: bold;
  text-align: left;
  padding-left: 4px;
}
.datatable caption {
  font: bold 0.9em Arial, Helvetica, sans-serif;
  color: #33517A;
  text-align: left;
  padding-top: 3px;
  padding-bottom: 8px;
}
.datatable tr:hover, .datatable tr.hilite {
  background-color: #DFE7F2;
  color: #000000;
}
</style>
</head>
<body>
<table summary="List of new students 2003" class="datatable">
 <caption>Student List</caption>
 <tr>
 <th scope="col">Student Name</th>
 <th scope="col">Date of Birth</th>
 <th scope="col">Class</th>
 <th scope="col">ID</th>
 </tr>
 <tr>
 <td>Joe Bloggs</td>
 <td>27/08/1997</td>
 <td>Mrs Jones</td>
 <td>12009</td>
 </tr>
 <tr>
 <td>William Smith</td>
 <td>20/07/1997</td>
 <td>Mrs Jones</td>
 <td>12010</td>
 </tr>
 <tr>
 <td>Jane Toad</td>
 <td>21/07/1997</td>
 <td>Mrs Jones </td>
 <td>12030</td>
 </tr>
 <tr>
 <td>Amanda Williams</td>
 <td>19/03/1997</td>
 <td>Mrs Edwards</td>
 <td>12021</td>
 </tr>
</table>
<script type="text/javascript">
var rows = document.getElementsByTagName('tr');
for (var i = 0; i < rows.length; i++) {
  rows[i].onmouseover = function() {
    this.className += ' hilite';
  }
  rows[i].onmouseout = function() {
    this.className = this.className.replace('hilite', '');
  }
}
</script>
</body>
</html>