prop和attr的比较
prop来获取或设置固有属性 removeProp() 删除固有属性
attr来获取或设置自定义属性 removeAttr() 删除自定义属性
案例：全选与全不选
<body>
<table border="1" cellpadding="5" cellspacing="0">
<thead>
<tr>
<th><input type="checkbox" id="theadCheckbox"/>id</th>
<th>姓名</th>
<th>性别</th>
<th>电话</th>
<th>年龄</th>
</tr>
</thead>
<tbody id="tbodyCheckbox">
<tr>
<td><input type="checkbox" id="" value="" name="boxs"/>1</td>
<td>张三</td>
<td>男</td>
<td>18210528452</td>
<td>20</td>
</tr>
<tr>
<td><input type="checkbox" id=" " value=" " name="boxs"/>2</td>
<td>张三</td>
<td>男</td>
<td>18210528452</td>
<td>20</td>
</tr>
<tr>
<td><input type="checkbox" id="" value="" name="boxs"/>3</td>
<td>张三</td>
<td>男</td>
<td>18210528452</td>
<td>20</td>
</tr>
<tr>
<td><input type="checkbox" id=" " value=" " name="boxs"/>4</td>
<td>张三</td>
<td>男</td>
<td>18210528452</td>
<td>20</td>
</tr>
<tr>
<td><input type="checkbox" id="" value="" name="boxs"/>5</td>
<td>张三</td>
<td>男</td>
<td>18210528452</td>
<td>20</td>
</tr>
</tbody>
</table>
</body>
<script>
$("#theadCheckbox").click(function(){
var flag=$(this).is(":checked");
if(flag){
$("#tbodyCheckbox").find(":checkbox").prop("checked",true)
}else{
$("#tbodyCheckbox").find(":checkbox").removeAttr("checked")
}
})
$("#tbodyCheckbox").find(":checkbox").click(function(){
var checkedLength=$("#tbodyCheckbox").find(":checked").length;
var checkboxLength=$("#tbodyCheckbox").find(":checkbox").length;
if(checkboxLength==checkedLength){
$("#theadCheckbox").prop("checked",true)
}else{
$("#theadCheckbox").removeAttr("checked")
</script>
