Javascript Static Singleton

In conventional software engineering, the singleton pattern can be implemented by creating a class with a method that creates a new instance of the class if one doesn't exist. In the event of an instance already existing, it simply returns a reference to that object.

jsfiddle link: http://jsfiddle.net/timsommer/thxn4/

var SingletonTester = (function () {
 //This is the actual singleton instance
 function Singleton() {
 this.name = "Singleton";
 this.pointX = 16;
 }

 // this is our instance holder
 var instance;

 // this is an emulation of static variables and methods
 var _static = {
 name: 'SingletonTester',
 // This is a method for getting an instance
 // It returns the same instance of the singleton object
 getInstance: function () {
 if (instance === undefined) {
 instance = new Singleton();
 }
 return instance;
 }
 };
 return _static;
})();

//getInstance method is the only method we can call on the returned _static object
var singletonTest = SingletonTester.getInstance();

console.log(singletonTest.pointX); // outputs 16
singletonTest.pointX = 15;
console.log(singletonTest.pointX); // outputs 15

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