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| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: c prog -plz explain |
| Date | 2014-03-11 11:47 -0700 |
| Organization | None to speak of |
| Message-ID | <lnmwgwshcm.fsf@nuthaus.mib.org> (permalink) |
| References | <71fb68ed-69a6-42da-b988-520f9c400ff4@googlegroups.com> <lfnf1j$mi3$1@dont-email.me> |
Ken Brody <kenbrody@spamcop.net> writes:
> On 3/10/2014 5:50 PM, SAHIL MAHLA wrote:
>> #include <stdio.h>
>> void incme(double *p)
>> {
>> *p += 1;
>> }
>>
>> int main(void)
>> {
>> int i = 1;
>> double j=i;
>> incme((double*)&i);
>> printf("%d,%g",i,j);
>> return 0;
>> }
> [...]
>
> "I took my box of salt, and with a marker I crossed out 'salt' and wrote
> 'sugar'. How come my tea tastes funny?"
>
> Just because you told the compiler to treat the pointer-to-int "&i" as if it
> were a pointer-to-double doesn't mean that what it points to really *is* a
> double.
Sahil: If you're new to the language, I suggest you'll have better luck
taking something you want to do and then figuring out how to do it,
rather than starting with some (in this case questionable) code and then
trying to figure out how it behaves and why.
Yet another silly analogy: If you have a hammer, you should probably try
to learn how to drive nails with it rather than starting out by asking
what happens if you try to drive screws with it. You'll have plenty of
opportunity to screw things up once you've mastered the basics.
And again, let me recommend http://www.c-faq.com/ as an excellent
resource (though as the name implies it's a collection of questions and
answers, not a tutorial).
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
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c prog -plz explain SAHIL MAHLA <sahilmehla@gmail.com> - 2014-03-10 14:50 -0700
Re: c prog -plz explain Keith Thompson <kst-u@mib.org> - 2014-03-10 15:41 -0700
Re: c prog -plz explain Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-03-10 23:21 +0000
Re: c prog -plz explain Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-03-10 23:24 +0000
Re: c prog -plz explain SAHIL MAHLA <sahilmehla@gmail.com> - 2014-03-10 20:28 -0700
Re: c prog -plz explain James Kuyper <jameskuyper@verizon.net> - 2014-03-11 00:15 -0400
Re: c prog -plz explain Kaz Kylheku <kaz@kylheku.com> - 2014-03-11 07:12 +0000
Re: c prog -plz explain Noob <root@127.0.0.1> - 2014-03-12 10:43 +0100
Re: c prog -plz explain Kaz Kylheku <kaz@kylheku.com> - 2014-03-12 14:38 +0000
Re: c prog -plz explain Noob <root@127.0.0.1> - 2014-03-12 15:56 +0100
Re: c prog -plz explain Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-03-12 11:16 -0400
Re: c prog -plz explain James Kuyper <jameskuyper@verizon.net> - 2014-03-12 11:36 -0400
Re: c prog -plz explain Kaz Kylheku <kaz@kylheku.com> - 2014-03-12 15:38 +0000
Re: c prog -plz explain glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-12 19:13 +0000
Re: c prog -plz explain Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-03-12 16:05 -0400
Re: c prog -plz explain James Kuyper <jameskuyper@verizon.net> - 2014-03-12 16:32 -0400
Re: c prog -plz explain Ian Collins <ian-news@hotmail.com> - 2014-03-13 09:38 +1300
Re: c prog -plz explain Tim Rentsch <txr@alumni.caltech.edu> - 2014-03-29 08:32 -0700
Re: c prog -plz explain glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-12 19:03 +0000
Re: c prog -plz explain James Kuyper <jameskuyper@verizon.net> - 2014-03-12 15:33 -0400
Re: c prog -plz explain Kaz Kylheku <kaz@kylheku.com> - 2014-03-12 20:56 +0000
Re: c prog -plz explain Ian Collins <ian-news@hotmail.com> - 2014-03-13 10:07 +1300
Re: c prog -plz explain "BartC" <bc@freeuk.com> - 2014-03-11 10:33 +0000
Re: c prog -plz explain Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2014-03-10 18:48 -0400
Re: c prog -plz explain SAHIL MAHLA <sahilmehla@gmail.com> - 2014-03-10 20:26 -0700
Re: c prog -plz explain Ian Collins <ian-news@hotmail.com> - 2014-03-11 16:34 +1300
typecasting (was Re: c prog -plz explain) Jorgen Grahn <grahn+nntp@snipabacken.se> - 2014-03-12 07:03 +0000
Re: typecasting (was Re: c prog -plz explain) Kaz Kylheku <kaz@kylheku.com> - 2014-03-12 07:40 +0000
Re: typecasting (was Re: c prog -plz explain) Lowell Gilbert <lgusenet@be-well.ilk.org> - 2014-03-12 10:47 -0400
Re: typecasting (was Re: c prog -plz explain) Ken Brody <kenbrody@spamcop.net> - 2014-03-12 13:01 -0400
Re: typecasting (was Re: c prog -plz explain) Richard <rgrdev_@gmail.com> - 2014-03-12 12:47 +0100
Re: typecasting (was Re: c prog -plz explain) gazelle@shell.xmission.com (Kenny McCormack) - 2014-03-12 12:39 +0000
Re: typecasting (was Re: c prog -plz explain) Kaz Kylheku <kaz@kylheku.com> - 2014-03-12 15:06 +0000
Re: c prog -plz explain Kaz Kylheku <kaz@kylheku.com> - 2014-03-11 07:26 +0000
Re: c prog -plz explain Richard <rgrdev_@gmail.com> - 2014-03-11 08:39 +0100
Re: c prog -plz explain Kaz Kylheku <kaz@kylheku.com> - 2014-03-11 08:08 +0000
Re: c prog -plz explain Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2014-03-11 09:14 -0400
Re: c prog -plz explain Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-03-11 15:38 +0000
Re: c prog -plz explain Ken Brody <kenbrody@spamcop.net> - 2014-03-11 12:53 -0400
Re: c prog -plz explain Keith Thompson <kst-u@mib.org> - 2014-03-11 11:47 -0700
Re: c prog -plz explain glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-11 21:41 +0000
Re: c prog -plz explain Kaz Kylheku <kaz@kylheku.com> - 2014-03-11 22:01 +0000
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