JSFiddle - React, Tailwind, and code Playground

JavaScript

var foo = (function() {
    //Private vars
    var a = 1;

    return {
        //Public vars/methods
        a: a,
        changeVar: function () {
            a = 2;
        }
    }
})();
alert(foo.a);
foo.changeVar();
alert(foo.a);