Re: Array initialisation

From:
Daniel Pitts <newsgroup.spamfilter@virtualinfinity.net>
Newsgroups:
comp.lang.java.programmer
Date:
Thu, 29 Nov 2007 10:16:40 -0800
Message-ID:
<1tadnSmvd8qwn9LanZ2dnUVZ_sfinZ2d@wavecable.com>
Jason Cavett wrote:

On Nov 29, 2:16 am, "Ouabaine" <ouaba...@orange.fr> wrote:

Hello,

When you create an array of numbers, like int array[]=new int[1000]; what is
the initial value of the array? Are all the members set to zero, or is it
undetermined?

Thanks


Just as an aside, Java provides a Collections framework which has
extensive support for array-type work but is generally faster/easier
to use/etc. It's not always right or feasible to use Collections, but
I just wanted to point them out in case you are learning Java and
didn't know about them.

http://java.sun.com/docs/books/tutorial/collections/index.html

A further aside.
While "it's not always right or feasible to use Collections" should be
phrased "In a few very specific circumstances you would choose Arrays of
Collections".

Using arrays in preference to collections is a form a primitive obsession.

<http://virtualinfinity.net/wordpress/program-design/2007/10/28/primitive-obsession/>

If you have a performance critical application *and a profiler tells you
that using collections is a bottleneck*, then you should *consider*
using arrays. Even before considering arrays, consider alternative
implementations of the Collection types your using (LinkedList Vs
ArrayList, HashSet vs TreeSet, etc...).

The only other time you should consider using Arrays is interfacing to
legacy code which doesn't have collections support. Even in that case,
its usually better to use a collection and then peform a toArray() call
when passing to the legacy code, and java.util.Arrays.asList() when
receiving from the legacy code.

--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/>

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