jquery如何获取后面三个tr与改面第三个tr内容
<!DOCTYPE?HTML>
<html>
<head>
<meta?charset=UTF-8?/>
<title>Nothing</title>
<style?type="text/css">
</style>
<script?type="text/javascript"?src="jquery-1.8.0.min.js"></script>
<script?type="text/javascript">
$?(function?()
{
var?trs?=?$?('table?tr');
var?last3trs?=?trs.filter?(":gt("?+?(trs.length?-?4)?+?")");
console.log?(last3trs.length);
trs.filter(":eq(3)").html("<td>1212121</td><td>afsadf</td><td>sss</td><td>adsfasdfasdf</td>");
})
</script>
</head>
<body>
<h1>网站列表</h1>
<table>
<tr>
<th?width="16">Id</th>
<th?width="64">名称</th>
<th?width="97">性质</th>
<th?width="191">URL</th>
</tr>
<tr>
<td>1</td>
<td>adsf</td>
<td>sdf</td>
<td>aaasdfasdf</td>
</tr>
<tr>
<td>2</td>
<td>aa</td>
<td>sdf</td>
<td>adfasdf</td>
</tr>
<tr>
<td>3</td>
<td>asdf</td>
<td>ddd</td>
<td>adsfasdfasdf</td>
</tr>
<tr>
<td>4</td>
<td>adfff</td>
<td>ddd</td>
<td>ddddddddddd</td>
</tr>
</table>
</body>
</html>