JSFiddle - React, Tailwind, and code Playground

HTML

<div></div>

JavaScript

Array.prototype.test= function() {
    alert("testing");
}

var x = [];
x.test();

NodeList.prototype.toArray = function() {
    var a = [];

    for (var i = 0, len = this.length; i < len; i++) {
        a[i] = this[i];
    }

    return a;
}
    
var tags = document.all.tags("div");
alert("NodeList: " + tags.length);
alert("Array: " + tags.toArray().length);