JSFiddle - React, Tailwind, and code Playground

HTML

<div id="test"> Hello </div>

JavaScript

var $ = function(id){
       return document.getElementById(id);
    };
    
    var iterations = 10000000;
    
    var start = new Date().getTime();
    for(var i = 0; i < iterations; i++){
        document.getElementById("test")
    }
    var end = new Date().getTime();  
    var time1 = end - start;
    console.log(time1)
    
    var start = new Date().getTime();
    for(var i = 0; i < iterations; i++){
        $("test")
    }
    var end = new Date().getTime();  
    var time2 = end - start;
    console.log(time2)
    
    alert( ((time2-time1)/time1)*100 + "% slower")