jquery Decision check box checkbox check number

Introduce jquery files first

<script type= "Text/javascript" src= "Js/jquery.js" ></script>

Determine if check is selected

Multi-selection box checkbox:

The code is as follows	Copy Code
$ ("#chk1"). attr ("Checked", "");/no tick. $ ("#chk2"). attr ("Checked", true);/tick if ($ ("#chk1"). attr (' checked ') ==undefined)//judge whether it has been ticked

Number of check box checkboxes read

The code is as follows	Copy Code
1.var num = $ (": input[name=color][checked]"). Length;

You can also write this:

The code is as follows	Copy Code
1.var num = $ (": input[name=color]:checked"). Length;

Both of these methods are compatible with IE, Firefox and Google browsers

jquery decision check box number of selected

1. $ ("input[type= ' checkbox '][name= ' Roleid '][checked=true]"). Length dynamically gets the number of selected

2. $ ("input[type= ' checkbox '][name= ' Roleid '][checked]"). Length dynamically gets the number of selected

3. $ ("input[type= ' checkbox '][name= ' Roleid ']checked"). Length is just the number of pages that contain checked