Re: Array initialisation

From:
Daniel Pitts <newsgroup.spamfilter@virtualinfinity.net>
Newsgroups:
comp.lang.java.programmer
Date:
Thu, 29 Nov 2007 10:38:32 -0800
Message-ID:
<K-mdnb-_O_msmtLanZ2dnUVZ_jadnZ2d@wavecable.com>
Patricia Shanahan wrote:

Daniel Pitts wrote:

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...).


I often choose arrays in preference to collections because of the better
notation for accessing and changing elements. Much more to do with code
clarity than with performance.

Patricia

Alas, if only Java supported proper operator overloading :-/

Code clarity for a fixed sized collection *maybe*. I still usually go
with collections. foo[1] isn't so concise that I fill bad about using
foo.get(1);

--
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