JSFiddle - React, Tailwind, and code Playground
by darkajax
HTML
<ul>
<li class="alpha"></li>
<li class="alpha"></li>
<li class="alpha"></li>
<li class="beta"></li>
<li class="alpha"></li>
<li class="beta"></li>
<li class="beta"></li>
<li class="alpha"></li>
<li class="beta"></li>
<li class="beta"></li>
</ul>
JavaScript
jQuery('ul li').each(function(){
var $current = $(this);
$current.text(($('ul li.' + $current.attr('class')).index($current) + 1))
});