jQuery toggleClass example
Toggle class name on click in jQuery
by Kelly Hawker
HTML
<table class="staff" border="1">
<tbody>
<tr>
<td>1</td>
<td>2</td>
<td>3</td>
<td>4</td>
<td>5</td>
<td>6</td>
<td>7</td>
<td>8</td>
<td>9</td>
<td>10</td>
<td>11</td>
<td>12</td>
<td>13</td>
</tr>
</tbody>
</table>
JavaScript
$(document).ready(function() {
let tds = $('table.staff').find('td');
let len = tds.length;
let itemsPerRow = 3;
for (var i = 0; i < len; i = i + itemsPerRow) {
$('table.staff').find('tbody')
.append($('<tr>')
.append(tds.splice(0, itemsPerRow))
);
}
});