Jquery1.6版本后attr的变化
Jquery1.6版本后attr的变化
2012 年 3 月 1 日 阿望 JAVASCRIPT, 0
认真地去看了官方的最新文档，当中有这样的一段话 = =！
可见，给YIN了吧。下面发个改动后的效果：
jquery1.6+版本：
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
//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'): falsejquery1.4 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 >
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
//
$("input").change(function() {
var $input = $(this);
$("p").html(".attr('checked'):
”
+ “.prop(‘checked’): ” + $input.prop(‘checked’) + “
”
+ “.is(‘:checked’): ” + $input.is(‘:checked’) ) + ““;
}).change();
// ]]>
转自 ：http://blog.phpbk.com/2012/03/jquery1-6%E7%89%88%E6%9C%AC%E5%90%8Eattr%E7%9A%84%E5%8F%98%E5%8C%96/