JSFiddle - React, Tailwind, and code Playground

JavaScript

var x = (function () {
                var privateMembers = { x: 0, y: 2, z: 5 };

                return {
                    toast: 123,
                    test1: function (arg) {
                        return this[arg];
                    },
                    test2: function () {
                        // ??
                    },
                    getPrivate: function (name) {
                        return privateMembers[name];
                    }
                };
            })();

            alert(x.getPrivate("y"));