javascript-singleton.js

var Application = window.Application || {}; // Creates a namespace called Application.
Application.Config = function () {
    var instance = (function () {
        var privateVar;
        function privateMethod() {
            return 'privateMethod';
        } 

        return { // Public interface.
            publicMethod: function () {
                return privateMethod();
            }
        }
    })(); 

    Application.Config = function() {
        return instance;
    } 

    return Application.Config();
}