Re: Newbie: cloning a Number

From:
Patricia Shanahan <pats@acm.org>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 27 Nov 2006 15:46:07 GMT
Message-ID:
<3LDah.3758$ql2.114@newsread3.news.pas.earthlink.net>
Philipp wrote:

Patricia Shanahan wrote:

Philipp wrote:

Hello
I have a class which take a Number as argument. I want to store it by
making a copy in a member of the class. I thought about using clone,
but my Eclipse IDE gives me an "Type mismatch: cannot convert from
Object to Number" error.
How should I do it? Thanks for your answers.
Phil


Number does not itself implement Cloneable, and immediately extends
Object, so I don't think it can be cloned.

Are you sure you need to clone the Number, rather than just keeping a
reference? There are a couple of new subclasses, AtomicInteger and
AtomicLong, but most Number subclasses have immutable objects.


Hello
Yes if subclasses of Number are immutable it really doesn't make much
sense to have a clone methode.

Thanks for that clarification.

I'm still surprised that it is not provided, even just for completness
(as well as for String, but there you have a copy ctor).
Is clone evil?

Phil


I don't understand clone's attraction for a class such as String, a
final class with immutable instances.

Perhaps you could explain why you would prefer a clone to a reference to
the original String?

Patricia

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