Re: enum or array ?

From:

"Mike Schilling" <mscottschilling@hotmail.com>

Newsgroups:

comp.lang.java.programmer

Date:

Fri, 29 May 2009 15:02:33 -0700

Message-ID:

<_XYTl.24709$as4.20115@nlpi069.nbdc.sbc.com>

Mark Space wrote:

Eric Sosman wrote:

Others have mentioned some "pros" of enums; I'll mention a
"con"
for the sake of balance (and because I'm a contrary sort of guy).

The con-stants of an enum are fixed at compile time and cannot
be
changed without recompilation.

This is a good point. If the OP is defining a set of parameters
that
his classes accept, then I think that's appropriate use of Enum. If
he's designing something that at all that reflects the need to alter
as the real world -- or some other system -- itself changes, then I
agree. Enums are limiting in this regard.

That's true. But it's quite possible (i.e. I've done it) to build a
class that mimics the code generated for Enums while allowing both
predefined values (which get static instances generated for them) plus
values added at runtime (which do not.) (In fact, since the Java
code for such a class is boilerplate, I've built a tool to generate
it.) You still get many of the advantages of enums, but not all: e.g.
you can't switch on them, nor can you override methods per-value.