JSFiddle - React, Tailwind, and code Playground

JavaScript

function Foo () {
  var bar = [];
  this.push = function (val) { bar.push(val); };
  this.get = function () { return bar; };
};

var a = new Foo();
var b = new Foo();
a.push(1);
a.push(2);
b.push(3);

console.log(a.get());
console.log(b.get());