Groups > comp.lang.java.programmer > #6985

Re: setSize ArrayList, when will it come?

From	Jan Burse <janburse@fastmail.fm>
Newsgroups	comp.lang.java.programmer
Subject	Re: setSize ArrayList, when will it come?
Date	2011-08-10 20:22 +0200
Organization	albasani.net
Message-ID	<j1ui9i$sh6$2@news.albasani.net> (permalink)
References	(3 earlier) <alpine.DEB.2.00.1108092230010.20857@urchin.earth.li> <j1scom$shp$1@news.albasani.net> <j1sebn$713$1@dont-email.me> <j1tbbu$5uu$1@news.albasani.net> <981db753-11a9-45da-aad4-a95c800cbab0@glegroupsg2000goo.googlegroups.com>

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Lew schrieb:
> 'ArrayList#ensureCapacity()'?
>
>> >  So now you can go about and kill whatever you like.
> Your objection?

Although it is a public method, it wouldn't work,
since it does not set the size field of the ArrayList.
So you only have as a post condition after ensureCapacity(n):

      elementData.length>=n

But not:

      size=n

You would still need to invoke a couple of add() calls
after calling ensureCapacity().

But calling ensureCapacity() before calling the add()s
would prevent gradually enlarging the ArrayList, so that
we would have a solution with zero unnecessary temporary
objects.

gr8 step forward, many thanks.

But still not what I consider an efficient solution. You
will burn some CPU cycles in the add()s call for nothing,
since the elementData is already nulled from Array.newInstance()
as required by the JLS.

So not a green solution.

Best Regards

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Thread

setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-09 00:47 +0200
  Re: setSize ArrayList, when will it come? Knute Johnson <september@knutejohnson.com> - 2011-08-08 16:53 -0700
    Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-09 02:30 +0200
  Re: setSize ArrayList, when will it come? Arne Vajhøj <arne@vajhoej.dk> - 2011-08-08 20:50 -0400
  Re: setSize ArrayList, when will it come? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-08-08 21:09 -0400
    Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-09 04:16 +0200
      Re: setSize ArrayList, when will it come? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-08-08 21:39 -0500
        Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-09 09:33 +0200
          Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-09 09:42 +0200
        Re: setSize ArrayList, when will it come? Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-09 07:56 +0000
          Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-09 11:18 +0200
          Re: setSize ArrayList, when will it come? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-08-09 10:36 -0500
            Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-09 18:30 +0200
              Re: setSize ArrayList, when will it come? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-08-09 16:30 -0500
                Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-10 00:31 +0200
                Re: setSize ArrayList, when will it come? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-08-09 20:36 -0500
                Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-10 09:04 +0200
                Re: setSize ArrayList, when will it come? Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-10 08:50 +0000
                Re: setSize ArrayList, when will it come? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-08-10 18:16 -0500
                Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-11 01:55 +0200
      Re: setSize ArrayList, when will it come? Patricia Shanahan <pats@acm.org> - 2011-08-09 01:33 -0700
        Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-09 11:16 +0200
          Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-09 11:32 +0200
            Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-09 11:35 +0200
          Re: setSize ArrayList, when will it come? Patricia Shanahan <pats@acm.org> - 2011-08-09 04:00 -0700
          Re: setSize ArrayList, when will it come? Arne Vajhøj <arne@vajhoej.dk> - 2011-08-09 20:11 -0400
      Re: setSize ArrayList, when will it come? Robert Klemme <shortcutter@googlemail.com> - 2011-08-10 10:21 +0200
        Re: setSize ArrayList, when will it come? Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-10 09:14 +0000
        Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-10 12:29 +0200
          Re: setSize ArrayList, when will it come? Robert Klemme <shortcutter@googlemail.com> - 2011-08-10 19:27 +0200
            Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-10 20:22 +0200
              Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-10 20:37 +0200
                Re: setSize ArrayList, when will it come? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-08-10 18:22 -0500
                Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-11 01:52 +0200
                Re: setSize ArrayList, when will it come? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-08-10 21:43 -0500
                Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-11 14:19 +0200
              Re: setSize ArrayList, when will it come? Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-10 22:23 +0000
                Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-11 01:47 +0200
                Re: setSize ArrayList, when will it come? Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-11 00:23 +0000
                Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-11 09:19 +0200
                Re: setSize ArrayList, when will it come? Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-12 15:06 +0000
  Re: setSize ArrayList, when will it come? Roedy Green <see_website@mindprod.com.invalid> - 2011-08-09 09:58 -0700
    Re: setSize ArrayList, when will it come? Patricia Shanahan <pats@acm.org> - 2011-08-09 10:25 -0700
      Re: setSize ArrayList, when will it come? Tom Anderson <twic@urchin.earth.li> - 2011-08-09 22:38 +0100
        Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-10 00:36 +0200
          Re: setSize ArrayList, when will it come? Roedy Green <see_website@mindprod.com.invalid> - 2011-08-09 15:55 -0700
          Re: setSize ArrayList, when will it come? Knute Johnson <september@knutejohnson.com> - 2011-08-09 16:03 -0700
            Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-10 09:18 +0200
              Re: setSize ArrayList, when will it come? Mayeul <mayeul.marguet@free.fr> - 2011-08-10 11:26 +0200
                Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-10 12:35 +0200
              Re: setSize ArrayList, when will it come? Lew <lewbloch@gmail.com> - 2011-08-10 09:33 -0700
                Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-10 20:22 +0200
          Re: setSize ArrayList, when will it come? Patricia Shanahan <pats@acm.org> - 2011-08-09 22:13 -0700
            Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-11 02:01 +0200
              Re: setSize ArrayList, when will it come? Patricia Shanahan <pats@acm.org> - 2011-08-10 18:42 -0700
                Re: setSize ArrayList, when will it come? Jan Burse <janburse@fastmail.fm> - 2011-08-11 14:21 +0200
    Re: setSize ArrayList, when will it come? Arne Vajhøj <arne@vajhoej.dk> - 2011-08-09 20:09 -0400
  Re: setSize ArrayList, when will it come? Roedy Green <see_website@mindprod.com.invalid> - 2011-08-09 16:02 -0700
    Re: setSize ArrayList, when will it come? Arne Vajhøj <arne@vajhoej.dk> - 2011-08-09 20:13 -0400

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