Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.java.programmer > #17806

Re: hashCode

Show all headers | View raw

  To: Eric Sosman
From: "=?UTF-8?B?QXJuZSBWYWpow7hq?=" <=?utf-8?b?qxjuzsbwywpow7hq?=@1:261/38.rem
ove-m2z-this>

  To: Eric Sosman
From: =?UTF-8?B?QXJuZSBWYWpow7hq?= <arne@vajhoej.dk>

On 8/11/2012 10:43 PM, Eric Sosman wrote:
>      The O.P. asked whether it would "be potentially better" if
> Object's hashCode() returned a constant.  He did *not* ask whether
> such an implementation would be correct; he only asked if it would
> "be potentially better."  Upon prompting he explained what he
> meant by "better," and in light of that explanation the answer
> to his original question is NO.  Discussions about "Oh, but it's
> CORRECT" are just red herrings; it's still not "better."


The original questions were:

#Is it always technically correct to override the hashCode function
#like so:
#
#       @Override
#       public int hashCode() {
#               return 1;
#       }

For which the answer is YES. Per documentation.

But with really poor performance in many relevant cases.

#Would it be potentially better if that was Object's implementation?

Which was clarified to:

#Better in the sense that you would never HAVE to override hashCode.

For which the answer is also YES. Per the previous.

But with the same performance note. And a big sigh because it seems to want to 
broaden bad performance from a single class to the entire programming style 
(multiple classes).

Arne

-+- BBBS/Li6 v4.10 Dada-1
 + Origin: Prism bbs (1:261/38)
-+- Synchronet 3.16a-Win32 NewsLink 1.98
Time Warp of the Future BBS - telnet://time.synchro.net:24

--- BBBS/Li6 v4.10 Dada-1
 * Origin: Prism bbs (1:261/38)
--- Synchronet 3.16a-Win32 NewsLink 1.98
Time Warp of the Future BBS - telnet://time.synchro.net:24

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

Thread

Re: hashCode "Lew" <lew@1:261/38.remove-nlb-this> - 2012-08-13 18:36 +0000
  Re: hashCode "Arne Vajhøj" <������
høj@1:261/38.remove-nlb-this> - 2012-08-13 18:36 +0000
    Re: hashCode "Arne Vajhøj" <������
høj@1:261/38.remove-nlb-this> - 2012-08-13 18:36 +0000
      Re: hashCode "Eric Sosman" <eric.sosman@1:261/38.remove-nlb-this> - 2012-08-13 18:36 +0000
        Re: hashCode "Arne Vajhøj" <������
høj@1:261/38.remove-nlb-this> - 2012-08-13 18:36 +0000

csiph-web