JSFiddle - React, Tailwind, and code Playground
HTML
<ul>
<li id="11" value="10">Item One</li>
<li id="22" value="20">Item Two</li>
<li id="33" value="30">Item three</li>
<li id="44" value="40">Item Four</li>
<li id="55" value="50">Item Five</li>
</ul>
<div id="demo">
</div>
JavaScript
var myVals = [];
$('li','ul').each(function(){
myVals.push($(this).attr('id'));
$('#demo').text(myVals[0]);
});