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| From | Richard Heathfield <rjh@cpax.org.uk> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: While or if: function to get next operator or operand |
| Date | 2015-11-20 16:47 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <n2nim6$oci$1@dont-email.me> (permalink) |
| References | <ca6f25b9-c067-4945-b4dd-2ba0a97ec136@googlegroups.com> <n2nhag$hv4$1@dont-email.me> <beead803-e6f9-487d-a3da-d2777d5ce30a@googlegroups.com> |
On 20/11/15 16:39, Alla _ wrote: > On Friday, November 20, 2015 at 8:24:14 PM UTC+4, Eric Sosman wrote: >> On 11/20/2015 11:06 AM, Alla _ wrote: >>> Hello! >>> >>> Please, take a look at the function below. It is from K&R. >>> >>> I dare to wonder why they use a while loop if the condition >>> considers only one item in the list. Why not to use if statement? >>> What is the purpose and the logic behind the while loop in this case? >>> [...] >>> /* the below while loop */ >>> while ((s[0] = c = getch()) == ' ' || c == '\t') >>> ; >> >> It's not looking at "only one item," it's looking at as many >> leading space or tab characters as getch() supplies. The loop >> terminates when the supplied character is something other than a >> space or tab, and that non-space/tab character is stored in s[0]. >> > No. Actually, yes. Eric Sosman is not infallible, but you'll have to work a lot harder than that to catch him out. He is quite right here (in fact, he is almost always quite right, and sometimes he's very, very right), and you are quite wrong to say otherwise on this occasion. > It looks if the input is equal to a space or a tab, and if yes, it > assigns a space or a tab to s[0]. And if *not*, it keeps looking. That's why it's a loop, not an if. -- Richard Heathfield Email: rjh at cpax dot org dot uk "Usenet is a strange place" - dmr 29 July 1999 Sig line 4 vacant - apply within
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While or if: function to get next operator or operand Alla _ <modelling.data@gmail.com> - 2015-11-20 08:06 -0800
Re: While or if: function to get next operator or operand Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-20 08:17 -0800
Re: While or if: function to get next operator or operand Richard Heathfield <rjh@cpax.org.uk> - 2015-11-20 16:44 +0000
Re: While or if: function to get next operator or operand Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-11-20 11:23 -0500
Re: While or if: function to get next operator or operand Alla _ <modelling.data@gmail.com> - 2015-11-20 08:39 -0800
Re: While or if: function to get next operator or operand Richard Heathfield <rjh@cpax.org.uk> - 2015-11-20 16:47 +0000
Re: While or if: function to get next operator or operand Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-11-20 11:54 -0500
Re: While or if: function to get next operator or operand Alla _ <modelling.data@gmail.com> - 2015-11-20 09:13 -0800
Re: While or if: function to get next operator or operand David Thompson <dave.thompson2@verizon.net> - 2015-12-06 08:04 -0500
Re: While or if: function to get next operator or operand James Kuyper <jameskuyper@verizon.net> - 2015-11-20 12:02 -0500
Re: While or if: function to get next operator or operand Richard Heathfield <rjh@cpax.org.uk> - 2015-11-20 16:41 +0000
Re: While or if: function to get next operator or operand Alla _ <modelling.data@gmail.com> - 2015-11-20 09:11 -0800
Re: While or if: function to get next operator or operand Richard Heathfield <rjh@cpax.org.uk> - 2015-11-20 17:39 +0000
Re: While or if: function to get next operator or operand Alla _ <modelling.data@gmail.com> - 2015-11-20 10:42 -0800
Re: While or if: function to get next operator or operand Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-11-21 14:58 -0500
Re: While or if: function to get next operator or operand Richard Heathfield <rjh@cpax.org.uk> - 2015-11-23 12:21 +0000
Re: While or if: function to get next operator or operand Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-21 21:29 +0000
Re: While or if: function to get next operator or operand BartC <bc@freeuk.com> - 2015-11-21 22:31 +0000
Re: While or if: function to get next operator or operand BartC <bc@freeuk.com> - 2015-11-22 10:57 +0000
Re: While or if: function to get next operator or operand Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-22 13:45 +0000
Re: While or if: function to get next operator or operand Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-11-22 01:31 -0500
Re: While or if: function to get next operator or operand Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-23 04:33 -0800
Re: While or if: function to get next operator or operand Philip Lantz <prl@canterey.us> - 2015-11-23 23:44 -0800
Re: While or if: function to get next operator or operand Rosario19 <Ros@invalid.invalid> - 2015-11-22 09:39 +0100
Re: While or if: function to get next operator or operand Rosario19 <Ros@invalid.invalid> - 2015-11-22 09:49 +0100
Re: While or if: function to get next operator or operand asetofsymbols@gmail.com - 2015-11-22 02:27 -0800
Re: While or if: function to get next operator or operand asetofsymbols@gmail.com - 2015-11-22 02:32 -0800
Re: While or if: function to get next operator or operand Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-11-22 10:02 -0500
Re: While or if: function to get next operator or operand Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-23 17:23 +0000
Re: While or if: function to get next operator or operand Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-11-23 12:31 -0500
Re: While or if: function to get next operator or operand Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-11-23 13:02 -0500
Re: While or if: function to get next operator or operand Alla _ <modelling.data@gmail.com> - 2015-11-22 07:06 -0800
Re: While or if: function to get next operator or operand Barry Schwarz <schwarzb@dqel.com> - 2015-11-22 11:43 -0800
Re: While or if: function to get next operator or operand Alla _ <modelling.data@gmail.com> - 2015-11-24 02:03 -0800
Re: While or if: function to get next operator or operand Alla _ <modelling.data@gmail.com> - 2015-11-24 02:11 -0800
Re: While or if: function to get next operator or operand James Kuyper <jameskuyper@verizon.net> - 2015-11-24 07:09 -0500
Re: While or if: function to get next operator or operand Richard Heathfield <rjh@cpax.org.uk> - 2015-11-23 12:26 +0000
Re: While or if: function to get next operator or operand raltbos@xs4all.nl (Richard Bos) - 2015-11-23 13:26 +0000
Re: While or if: function to get next operator or operand Alla _ <modelling.data@gmail.com> - 2015-11-22 07:17 -0800
Re: While or if: function to get next operator or operand James Kuyper <jameskuyper@verizon.net> - 2015-11-20 12:15 -0500
Re: While or if: function to get next operator or operand Alla _ <modelling.data@gmail.com> - 2015-11-20 10:44 -0800
Re: While or if: function to get next operator or operand Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-20 12:31 -0800
Re: While or if: function to get next operator or operand Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-11-20 15:38 -0500
Re: While or if: function to get next operator or operand James Kuyper <jameskuyper@verizon.net> - 2015-11-20 16:14 -0500
Re: While or if: function to get next operator or operand Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-11-20 16:55 -0500
Re: While or if: function to get next operator or operand Geoff <geoff@invalid.invalid> - 2015-11-20 15:04 -0800
Re: While or if: function to get next operator or operand Barry Schwarz <schwarzb@dqel.com> - 2015-11-20 20:59 -0800
Re: While or if: function to get next operator or operand Alla _ <modelling.data@gmail.com> - 2015-11-20 23:50 -0800
Re: While or if: function to get next operator or operand Alla _ <modelling.data@gmail.com> - 2015-11-21 00:18 -0800
Re: While or if: function to get next operator or operand Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-22 14:10 -0800
Re: While or if: function to get next operator or operand Philip Lantz <prl@canterey.us> - 2015-11-22 19:00 -0800
Re: While or if: function to get next operator or operand James Kuyper <jameskuyper@verizon.net> - 2015-11-23 06:57 -0500
Re: While or if: function to get next operator or operand Philip Lantz <prl@canterey.us> - 2015-11-23 23:49 -0800
Re: While or if: function to get next operator or operand James Kuyper <jameskuyper@verizon.net> - 2015-11-24 07:13 -0500
Re: While or if: function to get next operator or operand Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-23 07:55 -0800
Re: While or if: function to get next operator or operand Philip Lantz <prl@canterey.us> - 2015-11-23 23:36 -0800
Re: While or if: function to get next operator or operand Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-27 13:32 -0800
Re: While or if: function to get next operator or operand Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-11-20 16:13 -0500
Re: While or if: function to get next operator or operand Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-22 13:54 -0800
Re: While or if: function to get next operator or operand Geoff <geoff@invalid.invalid> - 2015-11-20 12:19 -0800
Re: While or if: function to get next operator or operand Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-20 15:32 -0800
Re: While or if: function to get next operator or operand Chad <cdalten@gmail.com> - 2015-11-20 18:38 -0800
Re: While or if: function to get next operator or operand Keith Thompson <kst-u@mib.org> - 2015-11-20 19:45 -0800
Re: While or if: function to get next operator or operand Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-20 20:12 -0800
Re: While or if: function to get next operator or operand Alla _ <modelling.data@gmail.com> - 2015-11-20 20:45 -0800
Re: While or if: function to get next operator or operand Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-20 21:04 -0800
Re: While or if: function to get next operator or operand Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-22 13:57 -0800
Re: While or if: function to get next operator or operand Alla _ <modelling.data@gmail.com> - 2015-11-20 20:43 -0800
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