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Groups > comp.lang.java.programmer > #11215
| From | Lew <noone@lewscanon.com> |
|---|---|
| Newsgroups | comp.lang.java.programmer |
| Subject | Re: Curious compiler warning |
| Date | 2012-01-10 21:46 -0800 |
| Organization | albasani.net |
| Message-ID | <jej7nu$tg2$1@news.albasani.net> (permalink) |
| References | <Xns9FD6D451D5F1Djpnasty@94.75.214.39> <jeir2s$7v0$3@news.albasani.net> <Xns9FD6F359B6B60jpnasty@94.75.214.39> |
Novice wrote:
> Lew wrote:
>> What's exactly wrong is that the assignment to the parameters is
>> thrown away, and does you no good.
>>
> How so? My original code says - in my opinion - "thank you very much for
> the value but we need to adjust it a little by subtracting one, aside
> from that, it's perfect". It's not like we're changing start to an
Nope. It says, "Subtract one from the value, extract the old value, then
store the new value back in the variable."
If all you needed was to subtract one, as is the case here, you'd only
subtract one and not store the result back. It's the store back that is
superfluous.
> arbitrary value like 0 or 5 billion regardless of the original value. The
A change is a change is a change. Why do you think that the new value has any
influence on that?
> code in this class basically just does String functions to count the
Your example showed absolutely no 'String' functions.
> number of occurrences of a string in another string but I'm assuming that
> the user will consider the initial character of the string being searched
> as '1' while Java's methods are all 0-based. I'm just subtracting one to
> bring the user's view of the situation in line with Java's view.
The word "just" means "and nothing else". This is not true in your example.
Your example *also* does something else, superfluously stores the new value
back to the variable. It also superfluously extracts the old value from the
value and ignores it.
> I'm just wondering why the compiler is so offended by "start--"....
That has been explained upthread. What remains unclear? We'll be happy to
fill in any missing details if you indicate what's missing.
>> public static int foo(int start, int finish) {
>>
>> /* Other stuff */
>>
>> bar(start - 1, finish - 1);
>> }
>>
>
> Yes, I definitely like that better. Strangely enough, writing
>
> bar(start--, finish--);
>
> gives me the same warning as before, presumably for the same reason.
Yes, the warning is for the same reason, but that code will have a different
effect.
Let's say you call 'foo(7, 3)'. The first version will call 'bar(6, 2)' (in
effect). The second will call 'bar(7, 3)'.
Do you get the reason for the warning (which you also called an error, of
which I approve)?
--
Lew
Honi soit qui mal y pense.
http://upload.wikimedia.org/wikipedia/commons/c/cf/Friz.jpg
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Curious compiler warning Novice <novice@example..com> - 2012-01-11 01:51 +0000
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-10 18:10 -0800
Re: Curious compiler warning glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-01-11 02:36 +0000
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-10 19:03 -0800
Re: Curious compiler warning glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-01-11 07:50 +0000
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-10 23:57 -0800
Re: Curious compiler warning Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-01-11 05:47 -0400
Re: Curious compiler warning glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-01-11 13:25 +0000
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-11 06:58 -0800
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-11 07:01 -0800
Re: Curious compiler warning Patricia Shanahan <pats@acm.org> - 2012-01-11 10:03 -0800
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-11 23:30 -0800
Re: Curious compiler warning Gene Wirchenko <genew@ocis.net> - 2012-01-11 18:10 -0800
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-11 23:32 -0800
Re: Curious compiler warning Leif Roar Moldskred <leifm@dimnakorr.com> - 2012-01-12 01:44 -0600
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-12 07:42 -0800
Re: Curious compiler warning Leif Roar Moldskred <leifm@dimnakorr.com> - 2012-01-12 10:51 -0600
Re: Curious compiler warning Patricia Shanahan <pats@acm.org> - 2012-01-12 07:50 -0800
Re: Curious compiler warning Leif Roar Moldskred <leifm@dimnakorr.com> - 2012-01-12 10:54 -0600
Re: Curious compiler warning Wanja Gayk <brixomatic@yahoo.com> - 2012-01-21 12:52 +0100
Re: Curious compiler warning Gene Wirchenko <genew@ocis.net> - 2012-01-12 11:51 -0800
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-12 20:58 -0800
Re: Curious compiler warning "Gavino" <invalid@invalid.invalid> - 2012-01-11 20:05 +0100
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-12 07:47 -0800
Re: Curious compiler warning Wanja Gayk <brixomatic@yahoo.com> - 2012-01-21 12:52 +0100
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-21 12:13 -0800
Re: Curious compiler warning Novice <novice@example..com> - 2012-01-11 04:55 +0000
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-10 21:46 -0800
Re: Curious compiler warning glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-01-11 07:55 +0000
Re: Curious compiler warning Roedy Green <see_website@mindprod.com.invalid> - 2012-01-11 01:35 -0800
Re: Curious compiler warning "Gavino" <invalid@invalid.invalid> - 2012-01-11 20:05 +0100
Re: Curious compiler warning Gene Wirchenko <genew@ocis.net> - 2012-01-11 18:18 -0800
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-12 07:55 -0800
Re: Curious compiler warning Gene Wirchenko <genew@ocis.net> - 2012-01-12 11:59 -0800
Re: Curious compiler warning Martin Gregorie <martin@address-in-sig.invalid> - 2012-01-13 00:02 +0000
Re: Curious compiler warning Patricia Shanahan <pats@acm.org> - 2012-01-12 16:11 -0800
Re: Curious compiler warning Martin Gregorie <martin@address-in-sig.invalid> - 2012-01-13 01:31 +0000
Re: Curious compiler warning Roedy Green <see_website@mindprod.com.invalid> - 2012-01-11 18:26 -0800
Re: Curious compiler warning Patricia Shanahan <pats@acm.org> - 2012-01-11 19:01 -0800
Re: Curious compiler warning Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-01-11 23:23 -0500
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-12 08:00 -0800
Re: Curious compiler warning Wanja Gayk <brixomatic@yahoo.com> - 2012-01-21 12:52 +0100
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-12 07:50 -0800
Re: Curious compiler warning Gene Wirchenko <genew@ocis.net> - 2012-01-11 18:14 -0800
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-12 08:05 -0800
Re: Curious compiler warning Gene Wirchenko <genew@ocis.net> - 2012-01-12 12:02 -0800
Re: Curious compiler warning Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-01-10 21:11 -0500
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-10 18:17 -0800
Re: Curious compiler warning bugbear <bugbear@trim_papermule.co.uk_trim> - 2012-01-11 16:10 +0000
Re: Curious compiler warning Lars Enderin <lars.enderin@telia.com> - 2012-01-11 20:45 +0100
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-12 08:09 -0800
Re: Curious compiler warning Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2012-01-12 18:14 +0200
Re: Curious compiler warning Wanja Gayk <brixomatic@yahoo.com> - 2012-01-21 12:52 +0100
Re: Curious compiler warning David Lamb <dalamb@cs.queensu.ca> - 2012-01-21 09:12 -0500
Re: Curious compiler warning Gene Wirchenko <genew@ocis.net> - 2012-01-11 18:21 -0800
Re: Curious compiler warning Lew <noone@lewscanon.com> - 2012-01-12 08:08 -0800
Re: Eclipse 3.7.1 compiler warning v_borchert@despammed.com (Volker Borchert) - 2012-01-11 21:10 +0000
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