Question

I have a confusion here.

If I cannot declare a class as static, how does enum works?
It looks like a static class, because it gets instantiated itself and can be called anywhere.
Looks like I can use enum almost like other static fields.

Is it safe to use enum?

Answer 1

enum types are automatically static. You can’t have a non-static enum, so the static is implied.

JLS 8.9:

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