JSFiddle - React, Tailwind, and code Playground

HTML

<ul id="catcher"></ul>

CSS

#catcher {border: 2px #ccc solid;padding: 20px;}

#catcher li {margin: 10px 0;}

JavaScript

/*
---
name: Core
description: Core helper functions for Mootools.
license: MIT-style license.
copyright: Copyright (c) Chase Wilson.
provides: [isCheckers]
...
*/
(function(){
    Native.implement({
        is:function(type){
          return typeOf(this)==type;   
        }
    });
})();

window.addEvent('domready',function(){
    var types = ['rad',3,'cool',2,function(){return '...';}, {object:'obj'}];
    
    types.each(function(it){
        var msg = '"'+it+'" is ';
        msg += it.isNumber?'a <code>number</code>.':'not a <code>number</code>.  ';
        msg += 'It\'s a <code>'+$type(it)+'</code>.';
        
        new Element('li',{html:msg}).inject($('catcher'));
    });
});