JSFiddle - React, Tailwind, and code Playground

HTML

<table>
	<thead>
		<tr>
			<th>Heading 1</th>
			<th>Heading 2</th>
			<th>Heading 3</th>
		</tr>
	</thead>
	<tbody>
		<tr>
			<td>Lorem</td>
			<td>lipsum</td>
			<td>dolor</td>
		</tr>
		<tr>
			<td>Lorem</td>
			<td>lipsum</td>
			<td>dolor</td>
		</tr>
	</tbody>
</table>

JavaScript

var $th = $("thead td");
var $td = $("tbody td")

var $th = $td.closest('table').find('th').eq($td.index());
$td.attr("data-attr", $th);