如何在ajax加载后获取datatable中的行数

<table id="myTable">
  <thead>
    <tr>
      <th>列1</th>
      <th>列2</th>
      <th>列3</th>
    </tr>
  </thead>
  <tbody></tbody>
</table>

$(document).ready(function() {
  $.ajax({
    url: 'your_data_url',
    type: 'GET',
    dataType: 'json',
    success: function(data) {
      var table = $('#myTable').DataTable({
        data: data,
        columns: [
          { data: 'column1' },
          { data: 'column2' },
          { data: 'column3' }
        ]
      });

      var rowCount = table.rows().count();
      console.log('行数：' + rowCount);
    }
  });
});