Nested Java enum definition - does declaring as static make a difference?

I have an interface - here's a nicely contrived version as an example:

public interface Particle {
    
    enum Charge {
        POSITIVE, NEGATIVE
    }

    Charge getCharge();
    
    double getMass();
    
    etc...
}

Is there any difference in how implementations of this would behave if I defined the Charge enum as static - i.e. does this have any effect:

public interface Particle {
    
    static enum Charge {
        POSITIVE, NEGATIVE
    }

    Charge getCharge();
    
    double getMass();
    
    etc...
}

No, it makes no difference. However the reason is not because it is a member declaration inside an interface, as Jon says. The real reason is according to language spec (8.9) that

> Nested enum types are implicitly > static. It is permissable to > explicitly declare a nested enum type > to be static.

At the following example static does not make any difference either (even though we have no interface):

public class A {
  enum E {A,B};
}

public class A {
  static enum E {A,B};
}

Another example with a nested private enum (not implicitly public).

public class A {
  private static enum E {A,B}
}

No, it makes no difference. From the language spec, section 9.5:

> Interfaces may contain member type > declarations (§8.5). A member type > declaration in an interface is > implicitly static and public.