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Groups > comp.lang.java.programmer > #23280
| From | Leif Roar Moldskred <leifm@dimnakorr.com> |
|---|---|
| Subject | Re: Usefulness of "final" |
| Newsgroups | comp.lang.java.programmer |
| References | (6 earlier) <qM6dnfaBydqB58HMnZ2dnUVZ8mmdnZ2d@bt.com> <m5js4x39je49.wr0biu59drh4.dlg@40tude.net> <kji61t$7u6$1@dont-email.me> <515cabb2$0$32111$14726298@news.sunsite.dk> <kjib26$914$1@dont-email.me> |
| Message-ID | <ud2dncO-I7NXj8DMnZ2dnUVZ7tudnZ2d@giganews.com> (permalink) |
| Date | 2013-04-04 00:42 -0500 |
markspace <markspace@nospam.nospam> wrote:
>
> Honestly I'm shocked at your response and I think you're missing the
> point by a wide margin. Are you trying to tell me that final fields are
> not involved in immutability in Java?
>
For what it's worth, they're not:
public class ThisIsImmutable {
private String cantChangeMe;
public ThisIsImmutable(String value) {
this.cantChangeMe = value;
}
public String getCantChangeMe() {
return this.cantChangeMe;
}
}
public class ThisIsNot {
private final Map<String, Integer> positionMap = new HashMap<>();
public void store(String key) {
this.positionMap.put(key, positionMap.size());
}
public Integer position(String key) {
return this.positionMap.get(key);
}
public void clear() {
this.positionMap.clear();
}
}
Now, it's certainly good practice to use "final" to help mark fields
that should not be reassigned, but "final" is neither sufficient nor
necessary to enforce immutability. (And with reflection mixed in the
bag it's not even sufficient to enforce non-reassignability, but
that's another story.)
As for the use of "final" for parameters and local variables, my
personal opinion is that the semantics of "final" are too weak to make
it worth the bother. As Java methods are pass-by-value, variable
reassignment just isn't a real source for problems so why guard
against it?
--
Leif Roar Moldskred
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Inserting In a List subhabangalore@gmail.com - 2013-04-02 03:11 -0700
Re: Inserting In a List Roedy Green <see_website@mindprod.com.invalid> - 2013-04-02 03:59 -0700
Re: Inserting In a List Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-04-02 08:27 -0300
Re: Inserting In a List Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-04-02 08:59 -0300
Re: Inserting In a List Martin Gregorie <martin@address-in-sig.invalid> - 2013-04-02 21:06 +0000
Re: Inserting In a List Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-04-02 18:22 -0400
Re: Inserting In a List Martin Gregorie <martin@address-in-sig.invalid> - 2013-04-02 22:52 +0000
Re: Inserting In a List Joerg Meier <joergmmeier@arcor.de> - 2013-04-03 02:04 +0200
Re: Inserting In a List Arne Vajhøj <arne@vajhoej.dk> - 2013-04-02 20:20 -0400
Re: Inserting In a List Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-04-02 21:03 -0400
Re: Inserting In a List Arne Vajhøj <arne@vajhoej.dk> - 2013-04-02 21:26 -0400
Re: Inserting In a List Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-04-02 22:29 -0400
Re: Inserting In a List Arne Vajhøj <arne@vajhoej.dk> - 2013-04-03 20:16 -0400
Re: Inserting In a List Joshua Cranmer 🐧 <Pidgeot18@verizon.invalid> - 2013-04-02 20:26 -0500
Re: Inserting In a List Arne Vajhøj <arne@vajhoej.dk> - 2013-04-02 21:29 -0400
Re: Inserting In a List Joerg Meier <joergmmeier@arcor.de> - 2013-04-04 14:07 +0200
Re: Inserting In a List Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-04-03 05:45 -0300
Re: Inserting In a List Joerg Meier <joergmmeier@arcor.de> - 2013-04-03 15:26 +0200
Re: Inserting In a List Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-04-03 18:09 -0300
Re: Inserting In a List Joerg Meier <joergmmeier@arcor.de> - 2013-04-04 00:54 +0200
Re: Inserting In a List Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-04-03 20:30 -0300
Re: Inserting In a List Joerg Meier <joergmmeier@arcor.de> - 2013-04-04 01:35 +0200
Re: Inserting In a List Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-04-03 20:55 -0300
Re: Inserting In a List Joerg Meier <joergmmeier@arcor.de> - 2013-04-04 02:00 +0200
Re: Inserting In a List Arne Vajhøj <arne@vajhoej.dk> - 2013-04-03 19:49 -0400
Re: Inserting In a List Martin Gregorie <martin@address-in-sig.invalid> - 2013-04-03 22:43 +0000
Re: Inserting In a List Joerg Meier <joergmmeier@arcor.de> - 2013-04-04 01:08 +0200
Re: Inserting In a List Martin Gregorie <martin@address-in-sig.invalid> - 2013-04-04 00:42 +0000
Re: Inserting In a List Joerg Meier <joergmmeier@arcor.de> - 2013-04-04 14:12 +0200
Re: Inserting In a List Martin Gregorie <martin@address-in-sig.invalid> - 2013-04-04 21:47 +0000
Re: Inserting In a List Joerg Meier <joergmmeier@arcor.de> - 2013-04-05 00:36 +0200
Re: Inserting In a List Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-04-02 21:08 -0400
Re: Inserting In a List Martin Gregorie <martin@address-in-sig.invalid> - 2013-04-03 22:37 +0000
Re: Inserting In a List Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-04-03 20:50 -0400
Re: Inserting In a List Joerg Meier <joergmmeier@arcor.de> - 2013-04-02 14:35 +0200
Re: Inserting In a List lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-02 15:08 +0100
Usefulness of "final" (Was: Re: Inserting In a List) Robert Klemme <shortcutter@googlemail.com> - 2013-04-02 21:06 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-04-02 16:41 -0400
Re: Usefulness of "final" (Was: Re: Inserting In a List) Robert Klemme <shortcutter@googlemail.com> - 2013-04-03 08:09 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) Arne Vajhøj <arne@vajhoej.dk> - 2013-04-03 20:13 -0400
Re: Usefulness of "final" (Was: Re: Inserting In a List) Arne Vajhøj <arne@vajhoej.dk> - 2013-04-02 20:08 -0400
Re: Usefulness of "final" (Was: Re: Inserting In a List) lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-03 11:15 +0100
Re: Usefulness of "final" (Was: Re: Inserting In a List) Robert Klemme <shortcutter@googlemail.com> - 2013-04-03 19:08 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-03 19:51 +0100
Re: Usefulness of "final" (Was: Re: Inserting In a List) Joerg Meier <joergmmeier@arcor.de> - 2013-04-03 21:01 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 14:15 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Arne Vajhøj <arne@vajhoej.dk> - 2013-04-03 18:22 -0400
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 15:41 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Arne Vajhøj <arne@vajhoej.dk> - 2013-04-03 19:56 -0400
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 16:58 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Arne Vajhøj <arne@vajhoej.dk> - 2013-04-03 20:08 -0400
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 17:21 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Arne Vajhøj <arne@vajhoej.dk> - 2013-04-03 20:27 -0400
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 17:34 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-04-03 21:20 -0400
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 19:17 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Lew <lewbloch@gmail.com> - 2013-04-03 20:45 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 21:30 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Joerg Meier <joergmmeier@arcor.de> - 2013-04-04 14:34 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-04 09:52 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Joerg Meier <joergmmeier@arcor.de> - 2013-04-05 00:39 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) Robert Klemme <shortcutter@googlemail.com> - 2013-04-04 19:50 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-04-04 08:27 -0400
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-04 09:47 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Robert Klemme <shortcutter@googlemail.com> - 2013-04-04 19:44 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-04 11:08 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Robert Klemme <shortcutter@googlemail.com> - 2013-04-04 22:53 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-04 14:29 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Robert Klemme <shortcutter@googlemail.com> - 2013-04-05 21:54 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-04 19:48 +0100
Re: Usefulness of "final" (Was: Re: Inserting In a List) Arne Vajhøj <arne@vajhoej.dk> - 2013-04-03 20:05 -0400
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 17:24 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Arne Vajhøj <arne@vajhoej.dk> - 2013-04-03 20:32 -0400
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 18:34 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Arne Vajhøj <arne@vajhoej.dk> - 2013-04-03 21:54 -0400
Re: Usefulness of "final" (Was: Re: Inserting In a List) Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-04-03 21:25 -0400
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 18:37 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Arne Vajhøj <arne@vajhoej.dk> - 2013-04-03 21:57 -0400
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 19:23 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Wanja Gayk <brixomatic@yahoo.com> - 2013-04-06 21:58 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-06 17:19 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Wanja Gayk <brixomatic@yahoo.com> - 2013-04-07 17:28 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-07 09:02 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Wanja Gayk <brixomatic@yahoo.com> - 2013-04-07 19:20 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) Wanja Gayk <brixomatic@yahoo.com> - 2013-04-07 19:24 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) Lew <lewbloch@gmail.com> - 2013-04-03 18:41 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Lew <lewbloch@gmail.com> - 2013-04-03 18:31 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 18:46 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Lew <lewbloch@gmail.com> - 2013-04-03 20:09 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 20:47 -0700
Re: Usefulness of "final" Leif Roar Moldskred <leifm@dimnakorr.com> - 2013-04-04 00:42 -0500
Re: Usefulness of "final" paul.cager@gmail.com - 2013-04-04 01:55 -0700
Re: Usefulness of "final" Joerg Meier <joergmmeier@arcor.de> - 2013-04-04 14:45 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) Joerg Meier <joergmmeier@arcor.de> - 2013-04-04 00:46 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 16:10 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Joerg Meier <joergmmeier@arcor.de> - 2013-04-04 01:25 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 16:44 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Joerg Meier <joergmmeier@arcor.de> - 2013-04-04 01:57 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 17:19 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Joerg Meier <joergmmeier@arcor.de> - 2013-04-04 14:35 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-04 10:34 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Joerg Meier <joergmmeier@arcor.de> - 2013-04-05 00:43 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-04 16:22 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Lew <lewbloch@gmail.com> - 2013-04-04 16:49 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-04 18:21 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Lew <lewbloch@gmail.com> - 2013-04-04 18:49 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-04-05 05:30 -0300
Re: Usefulness of "final" (Was: Re: Inserting In a List) Arne Vajhøj <arne@vajhoej.dk> - 2013-04-03 20:10 -0400
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-03 17:29 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) Joerg Meier <joergmmeier@arcor.de> - 2013-04-04 02:53 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) Jim Janney <jjanney@shell.xmission.com> - 2013-04-04 13:51 -0600
Re: Usefulness of "final" (Was: Re: Inserting In a List) Robert Klemme <shortcutter@googlemail.com> - 2013-04-06 13:31 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) markspace <markspace@nospam.nospam> - 2013-04-06 10:50 -0700
Re: Usefulness of "final" (Was: Re: Inserting In a List) lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-04 09:09 +0100
Re: Usefulness of "final" (Was: Re: Inserting In a List) Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-04-04 05:37 -0300
Re: Usefulness of "final" (Was: Re: Inserting In a List) Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-04-04 06:10 -0300
Re: Usefulness of "final" (Was: Re: Inserting In a List) Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-04-04 19:40 -0300
Re: arrays and variables Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-04-05 05:44 -0300
Re: arrays and variables lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-05 14:08 +0100
Re: arrays and variables Lew <lewbloch@gmail.com> - 2013-04-05 13:33 -0700
Re: arrays and variables lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-06 09:11 +0100
Re: arrays and variables Robert Klemme <shortcutter@googlemail.com> - 2013-04-06 15:20 +0200
Re: arrays and variables lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-06 16:25 +0100
Re: arrays and variables Robert Klemme <shortcutter@googlemail.com> - 2013-04-06 17:50 +0200
Re: arrays and variables lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-06 18:13 +0100
Re: arrays and variables Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-04-06 14:32 -0300
Re: arrays and variables Robert Klemme <shortcutter@googlemail.com> - 2013-04-06 15:02 +0200
Re: arrays and variables Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-04-05 22:12 -0300
Re: Usefulness of "final" (Was: Re: Inserting In a List) lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-04 10:35 +0100
Re: Usefulness of "final" (Was: Re: Inserting In a List) Joerg Meier <joergmmeier@arcor.de> - 2013-04-04 14:02 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-04 13:41 +0100
Re: Usefulness of "final" (Was: Re: Inserting In a List) Joerg Meier <joergmmeier@arcor.de> - 2013-04-04 13:53 +0200
Re: Usefulness of "final" (Was: Re: Inserting In a List) Robert Klemme <shortcutter@googlemail.com> - 2013-04-03 23:05 +0200
Re: Inserting In a List Joerg Meier <joergmmeier@arcor.de> - 2013-04-02 22:09 +0200
Re: Inserting In a List Arne Vajhøj <arne@vajhoej.dk> - 2013-04-02 20:03 -0400
Re: Inserting In a List Wanja Gayk <brixomatic@yahoo.com> - 2013-04-06 21:39 +0200
Re: Inserting In a List Robert Klemme <shortcutter@googlemail.com> - 2013-04-07 01:08 +0200
Re: Inserting In a List Lew <lewbloch@gmail.com> - 2013-04-06 22:15 -0700
Re: Inserting In a List lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-07 08:48 +0100
Re: Inserting In a List Lew <lewbloch@gmail.com> - 2013-04-07 12:32 -0700
Re: Inserting In a List "John B. Matthews" <nospam@nospam.invalid> - 2013-04-07 21:06 -0400
Re: Inserting In a List lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-08 08:40 +0100
Re: Inserting In a List lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-07 08:55 +0100
Re: Inserting In a List Wanja Gayk <brixomatic@yahoo.com> - 2013-04-07 17:54 +0200
Re: Inserting In a List lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-07 19:53 +0100
Re: Inserting In a List Arved Sandstrom <asandstrom2@eastlink.ca> - 2013-04-07 17:58 -0300
Re: Inserting In a List Robert Klemme <shortcutter@googlemail.com> - 2013-04-08 08:28 +0200
Re: Inserting In a List lipska the kat <"nospam at neversurrender dot co dot uk"> - 2013-04-08 08:54 +0100
Re: Inserting In a List Robert Klemme <shortcutter@googlemail.com> - 2013-04-08 19:13 +0200
Re: Inserting In a List Wanja Gayk <brixomatic@yahoo.com> - 2013-04-12 20:58 +0200
Re: Inserting In a List Lew <lewbloch@gmail.com> - 2013-04-12 13:17 -0700
Re: Inserting In a List Lew <lewbloch@gmail.com> - 2013-04-07 12:40 -0700
Re: Inserting In a List Wanja Gayk <brixomatic@yahoo.com> - 2013-04-12 20:47 +0200
Re: Inserting In a List Lew <lewbloch@gmail.com> - 2013-04-12 13:14 -0700
Re: Inserting In a List Steven Simpson <ss@domain.invalid> - 2013-04-02 13:53 +0100
Re: Inserting In a List Roedy Green <see_website@mindprod.com.invalid> - 2013-04-02 07:10 -0700
Re: Inserting In a List Lew <lewbloch@gmail.com> - 2013-04-02 10:46 -0700
Re: Inserting In a List markspace <markspace@nospam.nospam> - 2013-04-02 11:28 -0700
Re: Inserting In a List Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-04-02 16:00 -0400
Re: Inserting In a List subhabangalore@gmail.com - 2013-04-03 01:47 -0700
Re: Inserting In a List Steven Simpson <ss@domain.invalid> - 2013-04-03 10:35 +0100
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