JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li><span>Item 1</span><span class="num">30</span></li>
    <li><span>Item 2</span><span class="num">0</span></li>
    <li><span>Item 3</span><span class="num">20</span></li>
</ul>

CSS

.disabled{
    color:#ccc;
}

JavaScript

$('ul span.num').filter(function(){
    return $(this).text() == "0";
}).parent().addClass('disabled');