两个声明都是正确的，但它们有不同的语义。

Both declarations are correct but they have different semantics.

第一种类型的声明允许您创建对象的实例：

The first type of declaration allows you to create instances of your objects:

var t = new myObject();
// then use t
t.myProperty = "some value";

var otherT = new myObject();
otherT.myProperty = "some other value";

第二个几乎就像一个静态对象：

The second is almost like a static object:

myObject.myProperty = "some value";