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javaenumspackage-private

Why can a enum have a package-private constructor?


Since an enum constructor can only be invoked by its constants, why is it then allowed to be package-private?


Solution

  • The constructor actually isn't package-private... it's implicitly private the way interface methods are implicitly public even if you don't add the keyword.

    The relevant section of the JLS (§8.8.3) states:

    If no access modifier is specified for the constructor of a normal class, the constructor has default access.

    If no access modifier is specified for the constructor of an enum type, the constructor is private.

    It is a compile-time error if the constructor of an enum type (§8.9) is declared public or protected.