SO - 18098537

by Arun P Johny

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></div>
</div>

JavaScript

$(function(){
    var temp = {};    

    $('*').each(function(idx, el){
        var classNames = el.className;
        if(classNames){
            var classes = classNames.split(' ');
            $.each(classes, function(idx, clazz){
                temp[clazz] = true;
            });
        }
    });
    
    var result = $.map(temp, function(value, key){
        return key;
    })
    console.log(result);
    
});