Java what does a protected variable mean in enum type?

Question

In Java 9, I can write code like this:

enum Abc {
    A, B, C;
    static protected int foo = 4; // what is the purpose of the protected variables like this in enum?
}

I think it makes no sense, because we cannot inherit or implement an enum.

Edit: This question is the same with Why are protected members allowed in final java classes?

Protected also allows package access if I'm not mistaken. Doesn't answer your question, but just saying. — Mad Physicist, Mar 18 '18 at 01:03
this question cannot be duplicate of it. please remove this mark. I am asking about enum types. — 1 JustOnly 1, Mar 18 '18 at 01:19
@Makoto that’s possible since Java 5, when `enum` types were introduced. Ignoring the fact that this is an `enum`, you can write `/* not public */ class Abc { static protected int foo = 4; }` having an obsolete `protected` modifier, since Java 1.0… — Holger, Mar 20 '18 at 16:15

score 3 · Accepted Answer · answered Mar 18 '18 at 01:02

3

It means just what it always means: accessible only from subclasses or classes in the same package. You're right that since you can't inherit the class, it's not any different from a package-private field in practice.

answered Mar 18 '18 at 01:02

yshavit

42,327
7
87
124

Using `protected` modifier for a variable can be right option ? Perhaps no one uses this modifier in `enum` for a variable. right ? – 1 JustOnly 1 Mar 18 '18 at 01:08
1

If it does what you want, it's a right option. :-) I agree that stylistically, package-private is probably better. – yshavit Mar 18 '18 at 01:12

Java what does a protected variable mean in enum type?

1 Answers1