JSFiddle - React, Tailwind, and code Playground
HTML
<ul id="demo2" data-name="demo2">
<li data-value="here">here</li>
<li data-value="are">are</li>
<li data-value="some...">some</li>
<!-- notice that this tag is setting a different value :) -->
<li data-value="initial">initial</li>
<li data-value="tags">tags</li>
</ul>
JavaScript
$('li[data-value]').each(function(){
alert($(this).data("value"));
})