JSFiddle - React, Tailwind, and code Playground

HTML

<ul id = "qualquer">
    <li id = "listitem1" class = "middle_item">
    </li>
    <li id = "listitem2">
    </li>
    <li id = "listitem3">
    </li>
</ul>

JavaScript

var id = document.querySelector('.middle_item').id;
alert(id);