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Groups > comp.lang.java.programmer > #20431
| Newsgroups | comp.lang.java.programmer |
|---|---|
| Date | 2012-12-18 00:13 -0800 |
| Message-ID | <e6f674ec-f00d-4b22-bc02-e1c0ff9ff196@oi3g2000pbb.googlegroups.com> (permalink) |
| Subject | Need clarification on Object.equals. |
| From | "plewto@gmail.com" <plewto@gmail.com> |
In the following code Node is an abstract class and both Gate and
Monitor are extensions of Node. a and b are distinct objects yet
a.equals(b) is returning true.
public class Foo {
public static void main(String[] argv){
Node a = new Gate();
Monitor b = new Monitor();
System.out.println(a.equals(b)); // --> prints 'true'
}
}
The underlying production code is a bit complex to include here. My
understanding is that equals is true if, and only if, a and b are
exactly the same object. Here they are not even the same class.
I did do a test stripped down to the bare essence:
public class Foo {
public static void main(String[] argv){
Foo a = new Bar();
Foo b = new Bar();
System.out.println(a.equals(b)); // --> prints 'false'
}
}
class Bar extends Foo {}
In this case the results are as I expected, a.equals(b) --> false
What could be going on here?
java version 1.7.0_06 on 64-bit Fedora 17
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Need clarification on Object.equals. "plewto@gmail.com" <plewto@gmail.com> - 2012-12-18 00:13 -0800
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-18 10:39 +0000
Re: Need clarification on Object.equals. Roedy Green <see_website@mindprod.com.invalid> - 2012-12-18 04:48 -0800
Re: Need clarification on Object.equals. Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2012-12-18 10:56 -0800
Re: Need clarification on Object.equals. FredK <fred.l.kleinschmidt@gmail.com> - 2012-12-19 08:13 -0800
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-19 11:22 -0500
Re: Need clarification on Object.equals. Lars Enderin <lars.enderin@telia.com> - 2012-12-19 17:43 +0100
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-19 12:06 -0500
Re: Need clarification on Object.equals. Patricia Shanahan <pats@acm.org> - 2012-12-19 09:39 -0800
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-19 13:24 -0500
Re: Need clarification on Object.equals. FredK <fred.l.kleinschmidt@gmail.com> - 2012-12-19 11:23 -0800
Re: Need clarification on Object.equals. Patricia Shanahan <pats@acm.org> - 2012-12-19 08:25 -0800
Re: Need clarification on Object.equals. plewto@gmail.com - 2012-12-18 10:56 -0800
Re: Need clarification on Object.equals. Jim Janney <jjanney@shell.xmission.com> - 2012-12-18 14:24 -0700
Re: Need clarification on Object.equals. Patricia Shanahan <pats@acm.org> - 2012-12-18 13:52 -0800
Re: Need clarification on Object.equals. markspace <-@.> - 2012-12-18 10:24 -0800
Re: Need clarification on Object.equals. plewto@gmail.com - 2012-12-18 10:48 -0800
Re: Need clarification on Object.equals. David Lamb <dalamb@cs.queensu.ca> - 2012-12-18 14:01 -0500
Re: Need clarification on Object.equals. plewto@gmail.com - 2012-12-18 12:14 -0800
Re: Need clarification on Object.equals. plewto@gmail.com - 2012-12-18 12:17 -0800
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-18 22:16 -0500
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 10:20 +0000
Re: Need clarification on Object.equals. Patricia Shanahan <pats@acm.org> - 2012-12-19 03:22 -0800
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 12:06 +0000
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-19 09:07 -0500
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-19 09:09 -0500
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 14:36 +0000
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-19 09:42 -0500
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 15:05 +0000
Re: Need clarification on Object.equals. Lars Enderin <lars.enderin@telia.com> - 2012-12-19 16:15 +0100
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 15:47 +0000
Re: Need clarification on Object.equals. Lars Enderin <lars.enderin@telia.com> - 2012-12-19 16:57 +0100
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 16:51 +0000
Re: Need clarification on Object.equals. Lars Enderin <lars.enderin@telia.com> - 2012-12-19 18:12 +0100
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 17:27 +0000
Re: Need clarification on Object.equals. Gene Wirchenko <genew@telus.net> - 2012-12-19 11:40 -0800
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-19 10:17 -0500
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 15:40 +0000
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-19 10:50 -0500
Re: Need clarification on Object.equals. Lars Enderin <lars.enderin@telia.com> - 2012-12-19 17:01 +0100
Re: Need clarification on Object.equals. Gene Wirchenko <genew@telus.net> - 2012-12-19 10:22 -0800
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 18:49 +0000
Re: Need clarification on Object.equals. Gene Wirchenko <genew@telus.net> - 2012-12-19 11:41 -0800
Re: Need clarification on Object.equals. Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2012-12-19 17:05 -0800
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-20 08:34 +0000
Re: Need clarification on Object.equals. Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2012-12-20 07:27 -0800
Re: Need clarification on Object.equals. Gene Wirchenko <genew@telus.net> - 2012-12-20 09:04 -0800
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-20 18:10 +0000
Re: Need clarification on Object.equals. Lew <lewbloch@gmail.com> - 2012-12-20 11:08 -0800
Re: Need clarification on Object.equals. Peter Dunihơ <Np0eStPeAdM@NnOwSlPiAnMk.com> - 2012-12-21 07:50 +0000
Re: Need clarification on Object.equals. Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2012-12-21 07:30 -0800
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-21 17:09 +0000
Re: Need clarification on Object.equals. Leŵ <lewbl0ch@gmail.com> - 2012-12-23 00:54 +0000
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-21 12:23 -0500
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-21 17:38 +0000
Re: Need clarification on Object.equals. Arne Vajhoj <arne@vajhoj.dk> - 2012-12-23 00:50 +0000
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-21 08:39 +0000
Re: Need clarification on Object.equals. Gene Wirchenko <genew@telus.net> - 2012-12-20 13:39 -0800
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-21 08:34 +0000
Re: Need clarification on Object.equals. Leif Roar Moldskred <leifm@dimnakorr.com> - 2012-12-19 09:22 -0600
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 15:35 +0000
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-19 10:56 -0500
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 17:08 +0000
Re: Need clarification on Object.equals. Joshua Cranmer <Pidgeot18@verizon.invalid> - 2012-12-19 08:58 -0600
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 15:32 +0000
Re: Need clarification on Object.equals. Joshua Cranmer <Pidgeot18@verizon.invalid> - 2012-12-19 11:08 -0600
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 17:32 +0000
Re: Need clarification on Object.equals. Lars Enderin <lars.enderin@telia.com> - 2012-12-19 18:41 +0100
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 17:58 +0000
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 18:12 +0000
Re: Need clarification on Object.equals. Joshua Cranmer <Pidgeot18@verizon.invalid> - 2012-12-19 12:29 -0600
Re: Need clarification on Object.equals. Joshua Cranmer <Pidgeot18@verizon.invalid> - 2012-12-19 12:00 -0600
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 18:06 +0000
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-19 13:13 -0500
Re: Need clarification on Object.equals. Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2012-12-19 07:48 -0800
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 16:48 +0000
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-19 12:09 -0500
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 17:50 +0000
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-19 13:14 -0500
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 18:59 +0000
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-19 13:16 -0500
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 19:05 +0000
Re: Need clarification on Object.equals. Gene Wirchenko <genew@telus.net> - 2012-12-19 11:45 -0800
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 20:00 +0000
Re: Need clarification on Object.equals. Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2012-12-19 17:15 -0800
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-20 09:22 +0000
Re: Need clarification on Object.equals. Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2012-12-20 07:36 -0800
Re: Need clarification on Object.equals. Gene Wirchenko <genew@telus.net> - 2012-12-19 10:19 -0800
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-19 19:16 +0000
Re: Need clarification on Object.equals. Gene Wirchenko <genew@telus.net> - 2012-12-19 11:48 -0800
Re: Need clarification on Object.equals. Leif Roar Moldskred <leifm@dimnakorr.com> - 2012-12-19 14:12 -0600
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-19 09:04 -0500
Re: Need clarification on Object.equals. Lew <lewbloch@gmail.com> - 2012-12-19 13:40 -0800
Re: Need clarification on Object.equals. lipska the kat <lipskathekat@yahoo.co.uk> - 2012-12-20 09:30 +0000
Re: Need clarification on Object.equals. Lew <lewbloch@gmail.com> - 2012-12-18 12:52 -0800
Re: Need clarification on Object.equals. Joshua Cranmer <Pidgeot18@verizon.invalid> - 2012-12-19 09:27 -0600
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-19 10:44 -0500
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-18 22:11 -0500
Re: Need clarification on Object.equals. Arne Vajhøj <arne@vajhoej.dk> - 2012-12-18 22:10 -0500
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