Groups > comp.lang.java.programmer > #7153

Re: Using Enumerated Types as Array Indexes

From	Lew <lewbloch@gmail.com>
Newsgroups	comp.lang.java.programmer
Subject	Re: Using Enumerated Types as Array Indexes
Date	2011-08-16 20:45 -0700
Organization	http://groups.google.com
Message-ID	<6d418cda-dab3-43df-a9ec-293b43f2bbd8@glegroupsg2000goo.googlegroups.com> (permalink)
References	<b9ad6662-3240-4754-86a0-b715e8cdbc48@z7g2000vbp.googlegroups.com> <4e4b0d81$0$314$14726298@news.sunsite.dk> <j2f3ci$1lh$1@dont-email.me> <4e4b1fe4$0$314$14726298@news.sunsite.dk> <j2fc1g$b9j$1@dont-email.me>

Show all headers | View raw

On Tuesday, August 16, 2011 8:20:05 PM UTC-7, markspace wrote:
> On 8/16/2011 6:56 PM, Arne Vajhï¿½j wrote:
> > byte/short/int/long integer types
> 
> OK, you mean for indexes?  char works too, and long really doesn't -- it 
> has to be cast to an int.  For longs, Java recognizes the loss of 
> precision using long and requires that you acknowledge that the upper 
> bits will simply be truncated.

JLS 10:
"The variables contained in an array have no names; instead they are referenced by array access expressions that use nonnegative integer index values."

IOW, you never index arrays with a byte, char or short.  If you try, you get a widening conversion first, and if that results in a negative int value, you got problems.

-- 
Lew

Back to comp.lang.java.programmer | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

Using Enumerated Types as Array Indexes KevinSimonson <kvnsmnsn@hotmail.com> - 2011-08-16 07:53 -0700
  Re: Using Enumerated Types as Array Indexes Patricia Shanahan <pats@acm.org> - 2011-08-16 09:30 -0700
  Re: Using Enumerated Types as Array Indexes Tom Anderson <twic@urchin.earth.li> - 2011-08-16 21:37 +0100
  Re: Using Enumerated Types as Array Indexes Gene Wirchenko <genew@ocis.net> - 2011-08-16 14:54 -0700
    Re: Using Enumerated Types as Array Indexes Arne Vajhøj <arne@vajhoej.dk> - 2011-08-16 20:47 -0400
  Re: Using Enumerated Types as Array Indexes Arne Vajhøj <arne@vajhoej.dk> - 2011-08-16 20:38 -0400
    Re: Using Enumerated Types as Array Indexes markspace <-@.> - 2011-08-16 17:52 -0700
      Re: Using Enumerated Types as Array Indexes Arne Vajhøj <arne@vajhoej.dk> - 2011-08-16 21:56 -0400
        Re: Using Enumerated Types as Array Indexes markspace <-@.> - 2011-08-16 20:20 -0700
          Re: Using Enumerated Types as Array Indexes Lew <lewbloch@gmail.com> - 2011-08-16 20:45 -0700
            Re: Using Enumerated Types as Array Indexes Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-08-17 06:31 -0300
              Re: Using Enumerated Types as Array Indexes Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-17 13:28 +0000
                Re: Using Enumerated Types as Array Indexes Lew <lewbloch@gmail.com> - 2011-08-17 07:17 -0700
                Re: Using Enumerated Types as Array Indexes Robert Klemme <shortcutter@googlemail.com> - 2011-08-17 19:02 +0200
                Re: Using Enumerated Types as Array Indexes markspace <-@.> - 2011-08-17 16:09 -0700
                Re: Using Enumerated Types as Array Indexes Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-17 23:48 +0000
                Re: Using Enumerated Types as Array Indexes markspace <-@.> - 2011-08-17 17:34 -0700
                Re: Using Enumerated Types as Array Indexes Patricia Shanahan <pats@acm.org> - 2011-08-17 18:07 -0700
                Re: Using Enumerated Types as Array Indexes markspace <-@.> - 2011-08-18 08:22 -0700
                Re: Using Enumerated Types as Array Indexes Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-18 18:37 +0000
                Re: Using Enumerated Types as Array Indexes markspace <-@.> - 2011-08-18 11:50 -0700
                Re: Using Enumerated Types as Array Indexes Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-18 20:49 +0000
                Re: Using Enumerated Types as Array Indexes markspace <-@.> - 2011-08-18 14:48 -0700
                Re: Using Enumerated Types as Array Indexes Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-18 22:50 +0000
                Re: Using Enumerated Types as Array Indexes Arne Vajhøj <arne@vajhoej.dk> - 2011-08-17 21:49 -0400
                Re: Using Enumerated Types as Array Indexes Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-08-17 21:50 -0400
                Re: Using Enumerated Types as Array Indexes Robert Klemme <shortcutter@googlemail.com> - 2011-08-19 14:13 +0200
                Re: Using Enumerated Types as Array Indexes Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-19 20:05 +0000
                Re: Using Enumerated Types as Array Indexes Robert Klemme <shortcutter@googlemail.com> - 2011-08-20 00:20 +0200
                Re: Using Enumerated Types as Array Indexes Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-19 23:11 +0000
                Re: Using Enumerated Types as Array Indexes Robert Klemme <shortcutter@googlemail.com> - 2011-08-20 11:21 +0200
                Re: Using Enumerated Types as Array Indexes Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-20 11:45 +0000
                Re: Using Enumerated Types as Array Indexes Robert Klemme <shortcutter@googlemail.com> - 2011-08-20 15:23 +0200
                Re: Using Enumerated Types as Array Indexes Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-20 16:15 +0000
                Re: Using Enumerated Types as Array Indexes Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-08-17 21:34 -0400
                Re: Using Enumerated Types as Array Indexes Robert Klemme <shortcutter@googlemail.com> - 2011-08-18 07:58 +0200
                Re: Using Enumerated Types as Array Indexes Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-08-18 06:29 -0300
                Re: Using Enumerated Types as Array Indexes RedGrittyBrick <RedGrittyBrick@spamweary.invalid> - 2011-08-18 10:47 +0100
                Re: Using Enumerated Types as Array Indexes Lew <lewbloch@gmail.com> - 2011-08-18 11:35 -0700
                Re: Using Enumerated Types as Array Indexes Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-08-18 18:30 -0300
                Re: Using Enumerated Types as Array Indexes Robert Klemme <shortcutter@googlemail.com> - 2011-08-19 14:57 +0200
                Re: Using Enumerated Types as Array Indexes Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-19 20:10 +0000
                Re: Using Enumerated Types as Array Indexes Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-08-19 19:12 -0300
                Re: Using Enumerated Types as Array Indexes Robert Klemme <shortcutter@googlemail.com> - 2011-08-20 00:26 +0200
                Re: Using Enumerated Types as Array Indexes Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-19 22:59 +0000
          Re: Using Enumerated Types as Array Indexes Arne Vajhøj <arne@vajhoej.dk> - 2011-08-17 21:34 -0400
            Re: Using Enumerated Types as Array Indexes Arne Vajhøj <arne@vajhoej.dk> - 2011-08-17 21:46 -0400
              Re: Using Enumerated Types as Array Indexes markspace <-@.> - 2011-08-17 19:51 -0700
    Re: Using Enumerated Types as Array Indexes David Lamb <dalamb@cs.queensu.ca> - 2011-08-17 08:29 -0400
      Re: Using Enumerated Types as Array Indexes Robert Klemme <shortcutter@googlemail.com> - 2011-08-17 16:04 +0200
      Re: Using Enumerated Types as Array Indexes Arne Vajhøj <arne@vajhoej.dk> - 2011-08-17 21:51 -0400
  Re: Using Enumerated Types as Array Indexes Niklas Holsti <niklas.holsti@tidorum.invalid> - 2011-08-17 11:24 +0300
    Re: Using Enumerated Types as Array Indexes Arne Vajhøj <arne@vajhoej.dk> - 2011-08-17 21:55 -0400
      Re: Using Enumerated Types as Array Indexes Niklas Holsti <niklas.holsti@tidorum.invalid> - 2011-08-18 10:59 +0300
  Re: Using Enumerated Types as Array Indexes Roedy Green <see_website@mindprod.com.invalid> - 2011-08-17 22:09 -0700

csiph-web