JSFiddle - React, Tailwind, and code Playground
HTML
<table>
<tr class='1'>
<td>First</td>
</tr>
<tr class='1'>
<td>second</td>
</tr>
<tr class='2'>
<td>third</td>
</tr>
<tr class='3'>
<td>fourth</td>
</tr>
<tr class='3'>
<td>fifth</td>
</tr>
</table>
JavaScript
var $tds = $("td");
[].reverse.call($tds);
$tds.each(function() {
var $parentRow = $(this).parent(),
$firstTrSameClass = $("tr").filter("." +$parentRow.attr("class")).not($parentRow).first();
if ($firstTrSameClass.length > 0) {
$firstTrSameClass.append(this);
$parentRow.remove();
}
});