JSFiddle - React, Tailwind, and code Playground

HTML

<div class="comment">
<div class="commentact">
    Test1
</div>
</div>
<div class="comment">
<div class="commentact">
    Test2
</div>
</div>
<div class="comment">
<div class="commentact">
    Test3
</div>
</div>

JavaScript

$(function(){ // DOM ready

    $(".commentact").fadeTo(0, 0.2); // initial opacity

    $(".comment").hover(function( e ) {
       $(".commentact", this).stop().fadeTo(300, e.type=="mouseenter"?1:0.2);
    });
    
});