JSFiddle - React, Tailwind, and code Playground

HTML

<div id="block"></div>

CSS

#block {width:100px;height:100px;background:green;}

JavaScript

Number.prototype.round = function(n){ return parseFloat(this.toFixed(n)) }
Object.prototype.isInt = function(){  return  this instanceof Number && /^\d+$/.test(this.toString()) }





$(document).ready(function()
{
	// alert((3).isInt());
     $("#block").css("background","red")
     $("#block").slideUp();
    
})