JSFiddle - React, Tailwind, and code Playground

HTML

<div class="top">
    <div class="one two"><div class="inner"></div></div>
    <div></div>
</div>
<div class="top">
    <div class="four two"><div class="inner2"></div></div>
    <div class=""></div>
</div>

JavaScript

var classes = [];
    $('[class]').each(function(){
        $($(this).attr('class').split(' ')).each(function() { 
            if (this.length>0 && $.inArray(this.valueOf(), classes) === -1) {
                classes.push(this.valueOf());
            }    
        });
    });
    console.log("LIST START\n\n"+classes.join('\n')+"\n\nLIST END");