The problem of selecting all checkboxes can only be executed once

Phenomenon: When running for the first time, click select all the checkbox, you can select all, click again, you can cancel all. However, no matter how I clicked after that, it didn't work...

 

1. <input type="checkbox" id="selectAll_top" />select all<br />  
2. <input type="checkbox" name="sel" class="combinedPay" />1<br />  
3. <input type="checkbox" name="sel" class="combinedPay" />2<br />  
4. <input type="checkbox" name="sel" class="combinedPay" />3<br />  
5.   
6.   
7. <script type="text/javascript">  
8.     $("#selectAll_top").click(function(){  
9.         if($("#selectAll_top").prop('checked')){  
10.             $("#selectAll_end").attr("checked",true);  
11.             $(".combinedPay").attr("checked",true);  
12.         }else{  
13.             $("#selectAll_end").attr("checked",false);  
14.             $(".combinedPay").attr("checked",false);  
15.         }  
16.     });  
17. </script> 
    
    

    Solution:

    Try changing attr to prop.
    Some versions of jquery have this problem,
    mainly the problem of attribute values ​​and state values.