Javascript中的单例和原型(Singleton and Prototyping in Javascript)

 我只是在研究用JavaScript定义单例的方法，在查看了几个示例后，我想到了以下我没有找到的方法： 
 
function MyClass() {
   if (MyClass._sharedInstance === undefined) {
      // actual constructor code

      MyClass._sharedInstance = this;
   }
   return MyClass._sharedInstance;
}

MyClass._sharedInstance = undefined;
 
 似乎工作得很好......但我无法在任何地方找到这一点的事实让我怀疑。 有没有理由不以这种方式做单身，特别是考虑到JavaScript的许多小陷阱。 我知道通过简单地做一个var MyClass = { /* MyClass Stuff */ }我可以用更少的代码实现一个单例，但为了保持一致性，我想用原型定义所有类。 

I was just looking into ways of defining singletons in JavaScript, and after looking into a few samples I thought about the following way which I haven't found anywhere:
 
function MyClass() {
   if (MyClass._sharedInstance === undefined) {
      // actual constructor code

      MyClass._sharedInstance = this;
   }
   return MyClass._sharedInstance;
}

MyClass._sharedInstance = undefined;
 
Seems to work fine... but the fact that I couldn't find this anywhere makes me suspicious. Is there any reason not to do a singleton that way, especially considering the many little pitfalls of JavaScript. I know that by simply doing a var MyClass = { /* MyClass Stuff */ } I can achieve a singleton with less code, but for the sake of consistency I would like to define all my classes using prototypes.

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