How to get a count of checkboxes checked on pagination Jquery dataTables

Question

Below is my code, I want to get the count of checked checkboxes of all pages in my DataTable. Please advice how to proceed

 <td align="center"><input type="checkbox" align="center" id="all" class="groupCheckBox" name="emails[]" value=' . $user['id'] . '></td>

Below code I used for get the values of checked boxes in all pages on button click

 $('#merge_button').click(function () {   
         var id = ""; 
         var oTable = $("#userTable").dataTable(); 
         $(".groupCheckBox:checked", oTable.fnGetNodes()).each(function () { 

             if (id != "") { 
                 id = id + "," + $(this).val(); 
             } else { 
                 id = $(this).val(); 
             } 

             document.getElementById("email").value = id; 
         }); 
    }); 

but now I want to count the checkedboxes without button click function whenever user clicked on checkboxes and deduct count when unchecking boxes . pls advice

Answer 1

var table = $("#userTable").DataTable();

var countchecked = table
    .rows()
    .nodes()
    .to$()      // Convert to a jQuery object
.find('input[type="checkbox"].groupCheckBox:checked').length;

Uses the most recent API

"...please be aware that using deferRender will cause some nodes to be created only when they are required for display, so they might not be immediately available when this method is called." from https://datatables.net/reference/api/rows().nodes()

Answer 2

很简单。

$("td input[type='checkbox']:checked").length;