HTML Table to Json

     <table class="table table-striped table-bordered table-hover dataTable no-footer" id="boltAreaDetailType" role="grid" aria-describedby="sample_2_info">                                     <thead>                                         <tr>                                             <td data-override="BoltName" >螺栓型号</td>                                             <td data-override="BoltType">螺栓规格</td>                                             <td data-override="Num">数量</td>                                             <td>操作</td>                                         </tr>                                     </thead>                                     <tbody id="tableBoltAreaTypeBody"></tbody>                                 </table>

    var table = $('#boltAreaDetailType').tableToJSON({         extractor: {             0: function (cellIndex, $cell) {                 return $cell.find('option:selected').val();             },             1: function (cellIndex, $cell) {                 return $cell.find('option:selected').val();             },             2: function (cellIndex, $cell) {                 return $cell.find('input[type=number]').val();             }         },         ignoreColumns: [3]     });