Static variables in JavaScript

function MyClass () { // constructor function
  var privateVariable = "foo";   //NO:obj.privateVariable, MyClass.privateVariable; PS：不属于instance，只能在内部使用；
  this.publicVariable = "bar";   //YES:obj.publicVariable;    No:MyClass.publicVariable;
  this.privilegedMethod = function () {   //YES:obj.privilegedMethod();  NO:MyClass.privilegedMethod();
    alert(privateVariable);
  };
}
 
MyClass.prototype.publicMethod = function () {  //YES: obj.publicMethod();
  alert(this.publicVariable);
};
 
MyClass.staticProperty = "baz";   //YES: MyClass.staticProperty;
 
//...
var myInstance = new MyClass();