JSFiddle - React, Tailwind, and code Playground
HTML
<li class="ui-menu-item" role="presentation" data-name="0"> <a id="ui-id-2" class="ui-corner-all" tabindex="-1">AScript</a>
</li>
<li class="ui-menu-item" role="presentation" data-name="1"> <a id="ui-id-2" class="ui-corner-all" tabindex="-1">AScript</a>
</li>
<li class="ui-menu-item" role="presentation" data-name="2"> <a id="ui-id-2" class="ui-corner-all" tabindex="-1">AScript</a>
</li>
JavaScript
$('[data-name]').each(function (e) {
// Set the data-name to the item number
$(this).attr('data-name', e);
// Print the new `data-name` to the console
console.log($(this).attr('data-name'));
});