Jquery 获取Checkbox值，prop 和 attr 函数区别
总结：
| 版本 | 1.6 | 1.6 | 1.4 | 1.4 |
| 函数 | 勾选 | 取消勾选 | 勾选 | 取消勾选 |
attr('checked')
|
checked | undefined | true | false |
.prop('checked')
|
true | false | 1.6才有此方法 | |
.is(':checked')
|
true | false | true | false |
elem.checked
true (Boolean) Will change with checkbox state
$(elem).prop("checked")
true (Boolean) Will change with checkbox state
elem.getAttribute("checked")
"checked" (String) Initial state of the checkbox; does not change
$(elem).attr("checked")(1.6)
"checked" (String) Initial state of the checkbox; does not change
$(elem).attr("checked")(1.6.1+)
"checked" (String) Will change with checkbox state
$(elem).attr("checked")(pre-1.6)
true (Boolean) Changed with checkbox state
今天在用JQuery的时候发现一个问题用.attr("checked")获取checkbox的checked属性时选中的时候可以取到值,值为"checked"但没选中获取值就是undefined.
解决这个文章我参考了这个帖子：
http://bugs.jquery.com/ticket/9812
| Attribute/Property | .attr() |
.prop() |
|---|---|---|
| accesskey | √ | |
| align | √ | |
| async | √ | √ |
| autofocus | √ | √ |
| checked | √ | √ |
| class | √ | |
| contenteditable | √ | |
| draggable | √ | |
| href | √ | |
| id | √ | |
| label | √ | |
| location ( i.e. window.location ) | √ | √ |
| multiple | √ | √ |
| readOnly | √ | √ |
| rel | √ | |
| selected | √ | √ |
| src | √ | |
| tabindex | √ | |
| title | √ | |
| type | √ | |
width ( if needed over .width() ) |
√ |
下文来自www.jquery.com The difference between attributes and properties can be important in specific situations. Before jQuery 1.6, the .attr() method sometimes took property values into account when retrieving some attributes, which could cause inconsistent behavior. As of jQuery 1.6, the .prop()method provides a way to explicitly retrieve property values, while .attr() retrieves attributes For example, selectedIndex, tagName, nodeName, nodeType,ownerDocument, defaultChecked, and defaultSelected should be retrieved and set with the .prop() method. Prior to jQuery 1.6, these properties were retrievable with the .attr() method, but this was not within the scope of attr. These do not have corresponding attributes and are only properties.
elem.checked
true (Boolean) Will change with checkbox state
$(elem).prop("checked")
true (Boolean) Will change with checkbox state
elem.getAttribute("checked")
"checked" (String) Initial state of the checkbox; does not change
$(elem).attr("checked")(1.6)
"checked" (String) Initial state of the checkbox; does not change
$(elem).attr("checked")(1.6.1+)
"checked" (String) Will change with checkbox state
$(elem).attr("checked")(pre-1.6)
true (Boolean) Changed with checkbox state
原文:http://www.cnblogs.com/-run/archive/2011/11/16/2251569.html
1.6版情况：
//勾选后输出：
//attr('checked'): checked
//.prop('checked'): true
//.is(':checked'): true
//取消勾选输出：
//.attr('checked'): undefined
//.prop('checked'): false
//.is(':checked'): false
jquery1.4 版本：
1 <!DOCTYPE html>
2 <html>
3 <head>
4 <style>
5 p { margin: 20px 0 0 }
6 b { color: blue; }
7 </style>
8 <script src="../js/jquery-1.4.4.js"></script>
9 </head>
10 <body>
11
12 <input id="check1" type="checkbox" checked="checked">
13 <label for="check1">Check me</label>
14 <p></p>
15
16 <script>
17 $("input").change(function() {
18 var $input = $(this);
19 $("p").html(".attr('checked'): <b>" + $input.attr('checked') + "</b><br>"
20 + ".is(':checked'): <b>" + $input.is(':checked') ) + "</b>";
21 }).change();
22 </script>
23
24 </body>
25 </html>
勾选后输出：
//attr('checked'): true
//.prop('checked') 1.6后版本才有这个方法
//.is(':checked'): true
取消勾选输出：
//.attr('checked'): false
//.prop('checked')1.6后版本才有这个方法
//.is(':checked'): false
结论： attr('checked'): 在1.6后版本，所获取的值是 "checked"/"underfined" ，之前所获得的值是"false"/"true"。截然不同
