Answer by nullable for Singleton Pattern in Javascript

Not much going on here. The main focus should be on the constructor, it is returning an instantiated Universe for you. So anyone that calls it will have a reference to the same instance. Notice how the constructor is pointing to the Universe function.

I wouldn't use this pattern, as the new keyword implies a new instance is being created, and it seems a little too esoteric for my taste. In JS you can perfectly just have an object literal, often used with a namespace pattern:

(function(ns, window, undefined) {
    ns.singleton = {
        bang: 'Big'
    };

    window.ns = ns;
})(ns || {}, window);

console.log(window.ns.singleton.bang === 'Big');

Granted, this isn't a true singleton, but it does not need to be instantiated, and anyone who uses it will have the same values.

For more singleton implementations, see Javascript: best Singleton pattern