Sorry to sound stupid, but why would a class be static? I've encountered an example of anabstract static inner class and I'm not sure why it's static. Static methods I understand -- they are methods of the class and not the instance. So then, can someone explain to me astatic class?
Thanks,
Erik
You have encountered a static nested class (not a static inner class - an inner class is a nested class that is not static).
A static nested class is a nested class that does not require an instance of its enclosing class to exist in order that it can be instantiated. - It is mainly used for code organisation, and can be treated just like a top-level class.
In practice, most nested classes (except perhaps event handlers), tend to be static.
For an example of a static nested class from the core APIs, have a look at HasMap.Entry
> Excellent explanation. I understand now.
>
> Is "System.out" another example of a static nested
> class?
>
>
No, out is just a static member variable of the System class. You can't declare System.out objects. You can declare HashMap.Entry objects though.
> inner classes cannot be instantiated outside of object
> methods in the class, whereas static inner classes can
> be created anywhere
This is incorrect.
Inner classes _can_ be instantiated from anywhere that they are visible - if you declare an inner class public (inside a public class), and provide a public constructor, then it can be instantiated from anywhere.
