Uncaught TypeError: Cannot read property 'length' of undefined when trying to populate responsive datatable using php?

I am trying to fill responsive datatable with ajax request to a php script , the response is returned a JSON_encode format , i can see the response in xhr requests: ["abc","def","ght","jkl"]

Here is the code i am using

Name

                                    </tr>
                                </thead>
                             <tfoot>
        <tr>
            <th>Name</th>

        </tr>
    </tfoot>
    </table>




    $('#dataTables-example').DataTable({
            responsive: true,
               "ajax": "search_autocomplete.php",


    });

});

here is the php script-

   if ($result->num_rows >0) {
// output data of each row
while($row = $result->fetch_assoc()) {


    $list[] =$row['name'];

    }       
      echo json_encode( $list );            

}