Datatables ColVis JS HTML Columns

HTML

<link rel="stylesheet" href="https://cdn.datatables.net/1.10.12/css/jquery.dataTables.min.css">
<link rel="stylesheet" href="https://cdn.datatables.net/buttons/1.2.1/css/buttons.dataTables.min.css">
<script src="https://code.jquery.com/jquery-1.12.3.js"></script>
<script src="https://cdn.datatables.net/1.10.12/js/jquery.dataTables.min.js"></script>
<script src="https://cdn.datatables.net/buttons/1.2.1/js/dataTables.buttons.min.js"></script>
<script src="https://cdn.datatables.net/buttons/1.2.1/js/buttons.colVis.min.js"></script>
<table id="example" class="display" cellspacing="0" width="100%">
        <thead>
            <tr>
                <th class="show">Name</th>
                <th class="show">Position</th>
                <th class="hide">Office</th>
                <th class="hide">Age</th>
                <th class="show">Start date</th>
                <th class="show">Salary</th>
            </tr>
        </thead>
    </table>

JavaScript

$(document).ready(function() {
    $('#example').DataTable( {
        dom: 'Bfrtip',
        buttons: [
            {
                extend: 'colvis',
                columns: '.show'
            }
        ]
    } );
} );