JSFiddle - React, Tailwind, and code Playground

HTML

<div class="myClass"> my div </div>
<p class=""> my p </p>
<span> my span</span>
<br/>

JavaScript

//$(this).hasClass() always returns false
$('*').each(function() {
    if ($(this).hasClass() === false) {
        var class_name = $(this).attr('class');
        $("body").append($(this).prop("tagName") + " -> " +class_name+ "<br/>");
    }
});

$("body").append("<hr>");

//this one also returns the <p>
$("[class]").each(function(){
   var className = $(this).attr("class");
    $("body").append($(this).prop("tagName") + " -> " +className+ "<br/>");
})