public function ajax_list() {
    $list = $this->InfoTable_model->get_datatables();
    $data = array();
    $no = $_POST['start'];
    foreach ($list as $resident) {
        $no++;
        $row = array();
        // $row[] = '<td class="details-control"></td>';
        $row[] = ''; // how do i insert class here where this will generate <td> element
        $row[] = $resident->name;
        $row[] = $resident->lname;
        $row[] = $resident->gender;
        $row[] = date('m/d/Y', strtotime($resident->bday));
        $row[] = $resident->age;
        $row[] = $resident->citizenship;
        $row[] = $resident->occupation;
        $row[] = $resident->status;
        $row[] = $resident->purok;
        $row[] = $resident->resAddress;
        $row[] = $resident->perAddress;
        $row[] = $resident->telNum;
        $row[] = $resident->cpNum;

        //add html for action
        $row[] = '<a class="btn btn-sm btn-primary enable-tooltip" data-toggle="tooltip" href="javascript:void(0)" title="Edit Resident" onclick="edit_resident(' . "'" . $resident->resident_id . "'" . ')"><i class="fa fa-pencil"></i></a>
        <a class="btn btn-sm btn-danger enable-tooltip" data-toggle="tooltip" href="javascript:void(0)" title="Delete Resident" onclick="delete_resident(' . "'" . $resident->resident_id . "'" . ')"><i class="fa fa-times"></i></a>';

        $data[] = $row;
    }

    $output = array(
        "draw" => $_POST['draw'],
        "recordsTotal" => $this->InfoTable_model->count_all(),
        "recordsFiltered" => $this->InfoTable_model->count_filtered(),
        "data" => $data,
    );
    //output to json format
    echo json_encode($output);
}

var tableData = $('#table').dataTable({
            "oLanguage": {
                "sProcessing": '<center><i class="fa fa-asterisk fa-2x fa-spin text-info"></i></center>'
            },
            "processing": true, //Feature control the processing indicator.
            "serverSide": true, //Feature control DataTables' server-side processing mode.
            "order": [
                [1, 'asc']
            ], //Initial no order.
            // Load data for the table's content from an Ajax source
            "ajax": {
                "url": window.location.origin + "/InfoTable/ajax_list",
                "type": "POST"
            },
            //Set column definition initialisation properties.
            "columnDefs": [{
                "targets": [-1, 0], //last column
                "orderable": false //set not orderable
            }],
            "lengthMenu": [
                [5, 10, 15, 20, 25],
                [5, 10, 15, 20, 25]
            ]
        });