可见性:
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type="text/javascript" src="js/jquery-1.8.2.js"></script>
</head>
<body>
<table border="1" align="center">
<tr style="display:none">
<td>Value 1</td>
</tr>
<tr>
<td>Value 2</td>
</tr>
<tr>
<td>Value 3</td>
</tr>
</table>
<script type="text/javascript">
//1)查找隐藏的tr元素的个数
//alert( $("table tr:hidden").size() );
//2)查找所有可见的tr元素的个数
//alert( $("table tr:NOT(:hidden)").size() );
alert( $("table tr:visible").size() );//提倡
</script>
</body>
</html>
属性:
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type="text/javascript" src="../js/jquery-1.8.2.js"></script>
</head>
<body>
<div>
<p>Hello!</p>
</div>
<div id="test2"></div>
<input type="checkbox" name="newsletter" value="Hot Fuzz"/>
<input id="myID" type="checkbox" name="newsletter" value="Cold Fusion" />
<input type="checkbox" name="newsaccept" value="Evil Plans" />
<!--
<input type="checkbox" name="letternews" value="Hot Fuzz"/>
<input id="myID" type="checkbox" name="letnewster" value="Cold Fusion" />
<input type="checkbox" name="accNEWSept" value="Evil Plans" />
-->
<script type="text/javascript">
//1)查找所有含有id属性的div元素个数
//alert( $('div[id]').size() );
//2)查找所有name属性是newsletter的input元素,并将其选中
//$("input[name='newsletter']").attr("checked","checked");
//3)查找所有name属性不是newsletter的input元素,并将其选中
//$("input[name!='newsletter']").attr("checked","true");
/*
请问:在JS中如下符号表示什么意思
1)=/==/===
2)!=/!==
明天讲解
*/
//4)查找所有name属性以'news'开头的input元素,并将其选中
//$("input[name^='news']").attr("checked","checked");
//5)查找所有name属性以'letter'结尾的input元素,并将其选中
//$("input[name$='letter']").attr("checked","checked");
//6)查找所有name属性包含'news'的input元素,并将其选中
//$("input[name*='news']").attr("checked","checked");
//7)找到所有含有id属性,并且它的name属性是以"letter"结尾的input元素,并将其选中
$("input[id][name$='letter']").attr("checked","true");
</script>
</body>
</html>