JSFiddle - React, Tailwind, and code Playground

JavaScript

var Foo = function () { 
 
    var bar; 
 
    return { 
        getBar: function () { 
            return bar; 
        }, 
        setBar: function (b) { 
            bar = b; 
        } 
    }; 
};

var foo1 = new Foo(); 
foo1.setBar(123123); 
 
alert(foo1.getBar()); // alerts '3', OK 
 
var foo2 = new Foo(); 
foo2.setBar(4); 
 
alert(foo2.getBar()); // alerts '4', OK 
alert(foo1.getBar()); // alerts '4', NOT OK!