Singleton

singleton.js

var Singleton = (function () {
    var instance;
    function createInstance() {
        var object = new Object("I am the instance");
        return object;
    }
    return {
        getInstance: function () {
            // creates instans if it doesn't exist
            if (!instance) {
                instance = createInstance();
            }
            return instance;
        }
    };
})();
// Usage:
// Creates new instance
var instance1 = Singleton.getInstance();
var instance2 = Singleton.getInstance();
// Outputs: true
console.log(instance1 === instance2);