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| From | Ben Bacarisse <ben.usenet@bsb.me.uk> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: setting pointers to NULL and testing question. |
| Date | 2016-06-13 19:31 +0100 |
| Organization | A noiseless patient Spider |
| Message-ID | <87a8ip2b5a.fsf@bsb.me.uk> (permalink) |
| References | (3 earlier) <njm3h2$hml$1@dont-email.me> <njm52j$n6k$1@dont-email.me> <njm623$rs4$1@dont-email.me> <87vb1d2mo3.fsf@bsb.me.uk> <njmnb2$tcb$1@dont-email.me> |
BartC <bc@freeuk.com> writes:
> On 13/06/2016 15:22, Ben Bacarisse wrote:
>> BartC <bc@freeuk.com> writes:
>
>>> Oh, in that case Richard Heathfield's reply makes my point better.
>>
>> Richard's point seems to be that more complicated examples exist.
>>
>>> You don't really want to worry about the addition of an outer block
>>> later on limiting the scope of the variable, so that references to it
>>> outside the block instead resolve to a more global version.
>>
>> I don't follow this but does not seem to be what Richard said.
>
> If you start with this (w,x,y,z are just other bits of code):
>
> float p;
> void f(void) {
> int p;
>
> w;
> x;
> p=0;
> y;
> z=p;
>
> change it to this to make it more trendy:
>
> float p;
> void f(void) {
> w;
> x;
> int p=0;
> y;
> z=p;
>
> but then later a block needs to be inserted:
>
> float p;
> void f(void) {
> w;
> while (w) {
> x;
> int p=0;
> y;
> }
> z=p;
>
> This will still compile, but the z=p will now refer to the outer
> 'float p'. This is the problem with scattering declarations about all
> over the shop instead of segregating them. You have to keep track and
> what's what and where.
The same happens if I put the while loop here:
float p;
void f(void) {
while (...) {
int p;
w;
x;
p=0;
y;
}
z=p;
Show me almost any piece of code and I'll break it by adding a while
loop to it incorrectly. I don't think that fact tells us very much
about the value of the features that contribute to such breakages.
(Of course the main problem here is that the code was bad to start with.
Shadowing a file-scope name in a function is not a good idea.)
<snip>
--
Ben.
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setting pointers to NULL and testing question. G G <gdotone@gmail.com> - 2016-06-12 16:21 -0700
Re: setting pointers to NULL and testing question. Richard Heathfield <rjh@cpax.org.uk> - 2016-06-13 00:50 +0100
Re: setting pointers to NULL and testing question. G G <gdotone@gmail.com> - 2016-06-12 17:03 -0700
Re: setting pointers to NULL and testing question. Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-06-12 20:25 -0600
Re: setting pointers to NULL and testing question. James Kuyper <jameskuyper@verizon.net> - 2016-06-12 22:57 -0400
Re: setting pointers to NULL and testing question. Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-06-13 10:03 -0600
Re: setting pointers to NULL and testing question. Tim Rentsch <txr@alumni.caltech.edu> - 2016-06-15 14:43 -0700
Re: setting pointers to NULL and testing question. supercat@casperkitty.com - 2016-06-13 08:06 -0700
Re: setting pointers to NULL and testing question. Richard Damon <Richard@Damon-Family.org> - 2016-06-16 08:27 -0400
Re: setting pointers to NULL and testing question. supercat@casperkitty.com - 2016-06-16 06:27 -0700
Re: setting pointers to NULL and testing question. supercat@casperkitty.com - 2016-06-16 07:31 -0700
Re: setting pointers to NULL and testing question. Richard Damon <Richard@Damon-Family.org> - 2016-06-18 13:39 -0400
Re: setting pointers to NULL and testing question. supercat@casperkitty.com - 2016-06-18 11:37 -0700
Re: setting pointers to NULL and testing question. Richard Damon <Richard@Damon-Family.org> - 2016-06-18 17:17 -0400
Re: setting pointers to NULL and testing question. supercat@casperkitty.com - 2016-06-18 17:22 -0700
Re: setting pointers to NULL and testing question. James Kuyper <jameskuyper@verizon.net> - 2016-06-13 14:10 -0400
Re: setting pointers to NULL and testing question. Keith Thompson <kst-u@mib.org> - 2016-06-13 11:28 -0700
Re: setting pointers to NULL and testing question. Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-06-13 12:31 -0600
Re: setting pointers to NULL and testing question. Keith Thompson <kst-u@mib.org> - 2016-06-12 19:38 -0700
Re: setting pointers to NULL and testing question. Richard Heathfield <rjh@cpax.org.uk> - 2016-06-13 07:35 +0100
Re: setting pointers to NULL and testing question. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-06-13 11:40 +0100
Re: setting pointers to NULL and testing question. BartC <bc@freeuk.com> - 2016-06-13 11:56 +0100
Re: setting pointers to NULL and testing question. Martin Shobe <mashobe9@gmail.com> - 2016-06-13 06:22 -0500
Re: setting pointers to NULL and testing question. BartC <bc@freeuk.com> - 2016-06-13 12:39 +0100
Re: setting pointers to NULL and testing question. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-06-13 15:22 +0100
Re: setting pointers to NULL and testing question. BartC <bc@freeuk.com> - 2016-06-13 17:34 +0100
Re: setting pointers to NULL and testing question. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-06-13 19:31 +0100
Re: setting pointers to NULL and testing question. BartC <bc@freeuk.com> - 2016-06-13 20:17 +0100
Re: setting pointers to NULL and testing question. Keith Thompson <kst-u@mib.org> - 2016-06-13 12:47 -0700
Re: setting pointers to NULL and testing question. Tim Rentsch <txr@alumni.caltech.edu> - 2016-06-15 16:44 -0700
Re: setting pointers to NULL and testing question. Keith Thompson <kst-u@mib.org> - 2016-06-15 17:20 -0700
Re: setting pointers to NULL and testing question. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-06-13 04:01 -0700
Re: setting pointers to NULL and testing question. Tim Rentsch <txr@alumni.caltech.edu> - 2016-06-16 12:57 -0700
Re: setting pointers to NULL and testing question. Richard Heathfield <rjh@cpax.org.uk> - 2016-06-13 12:18 +0100
Re: setting pointers to NULL and testing question. David Brown <david.brown@hesbynett.no> - 2016-06-13 14:01 +0200
Re: setting pointers to NULL and testing question. Richard Heathfield <rjh@cpax.org.uk> - 2016-06-13 14:15 +0100
Re: setting pointers to NULL and testing question. David Brown <david.brown@hesbynett.no> - 2016-06-13 15:37 +0200
Re: setting pointers to NULL and testing question. Richard Heathfield <rjh@cpax.org.uk> - 2016-06-13 14:48 +0100
Re: setting pointers to NULL and testing question. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-06-13 15:43 +0100
Re: setting pointers to NULL and testing question. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-06-12 17:54 -0700
Re: setting pointers to NULL and testing question. John Bode <jfbode1029@gmail.com> - 2016-06-14 08:36 -0700
Re: setting pointers to NULL and testing question. Richard Heathfield <rjh@cpax.org.uk> - 2016-06-14 16:41 +0100
Re: setting pointers to NULL and testing question. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-06-14 09:01 -0700
Re: setting pointers to NULL and testing question. "James R. Kuyper" <jameskuyper@verizon.net> - 2016-06-14 13:25 -0400
Re: setting pointers to NULL and testing question. supercat@casperkitty.com - 2016-06-14 10:48 -0700
Re: setting pointers to NULL and testing question. Ian Collins <ian-news@hotmail.com> - 2016-06-15 08:24 +1200
Re: setting pointers to NULL and testing question. "James R. Kuyper" <jameskuyper@verizon.net> - 2016-06-14 16:57 -0400
Re: setting pointers to NULL and testing question. supercat@casperkitty.com - 2016-06-14 14:29 -0700
Re: setting pointers to NULL and testing question. BartC <bc@freeuk.com> - 2016-06-14 22:41 +0100
Re: setting pointers to NULL and testing question. supercat@casperkitty.com - 2016-06-14 15:16 -0700
Re: setting pointers to NULL and testing question. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-06-15 00:25 +0100
Re: setting pointers to NULL and testing question. Keith Thompson <kst-u@mib.org> - 2016-06-14 16:58 -0700
Re: setting pointers to NULL and testing question. David Brown <david.brown@hesbynett.no> - 2016-06-15 09:28 +0200
Re: setting pointers to NULL and testing question. Keith Thompson <kst-u@mib.org> - 2016-06-15 09:57 -0700
Re: setting pointers to NULL and testing question. David Brown <david.brown@hesbynett.no> - 2016-06-15 09:23 +0200
Re: setting pointers to NULL and testing question. Richard Heathfield <rjh@cpax.org.uk> - 2016-06-15 08:35 +0100
Re: setting pointers to NULL and testing question. Richard Heathfield <rjh@cpax.org.uk> - 2016-06-15 08:37 +0100
Re: setting pointers to NULL and testing question. David Brown <david.brown@hesbynett.no> - 2016-06-15 10:42 +0200
Re: setting pointers to NULL and testing question. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-06-15 13:28 +0100
Re: setting pointers to NULL and testing question. supercat@casperkitty.com - 2016-06-15 11:41 -0700
Re: setting pointers to NULL and testing question. raltbos@xs4all.nl (Richard Bos) - 2016-06-15 19:43 +0000
Re: setting pointers to NULL and testing question. supercat@casperkitty.com - 2016-06-15 13:09 -0700
Re: setting pointers to NULL and testing question. David Brown <david.brown@hesbynett.no> - 2016-06-15 22:31 +0200
Re: setting pointers to NULL and testing question. Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-06-15 17:11 -0400
Re: setting pointers to NULL and testing question. raltbos@xs4all.nl (Richard Bos) - 2016-06-18 20:44 +0000
Re: setting pointers to NULL and testing question. Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-06-18 17:20 -0400
Re: setting pointers to NULL and testing question. Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-06-14 23:22 -0700
Re: setting pointers to NULL and testing question. Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-06-15 13:23 +0100
Re: setting pointers to NULL and testing question. John Bode <jfbode1029@gmail.com> - 2016-06-20 13:36 -0700
Re: setting pointers to NULL and testing question. Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-06-14 14:59 -0400
Re: setting pointers to NULL and testing question. "James R. Kuyper" <jameskuyper@verizon.net> - 2016-06-14 15:17 -0400
Re: setting pointers to NULL and testing question. Richard Heathfield <rjh@cpax.org.uk> - 2016-06-14 20:25 +0100
Re: setting pointers to NULL and testing question. Tim Rentsch <txr@alumni.caltech.edu> - 2016-06-15 19:48 -0700
Re: setting pointers to NULL and testing question. Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-06-15 23:25 -0400
Re: setting pointers to NULL and testing question. James Kuyper <jameskuyper@verizon.net> - 2016-06-16 12:11 -0400
Re: setting pointers to NULL and testing question. supercat@casperkitty.com - 2016-06-16 09:25 -0700
Re: setting pointers to NULL and testing question. Tim Rentsch <txr@alumni.caltech.edu> - 2016-06-16 21:46 -0700
Re: setting pointers to NULL and testing question. Gareth Owen <gwowen@gmail.com> - 2016-06-17 06:13 +0100
Re: setting pointers to NULL and testing question. Robert Wessel <robertwessel2@yahoo.com> - 2016-06-17 02:03 -0500
Re: setting pointers to NULL and testing question. Martin Shobe <mashobe9@gmail.com> - 2016-06-17 07:07 -0500
Re: setting pointers to NULL and testing question. supercat@casperkitty.com - 2016-06-17 03:18 -0700
Re: setting pointers to NULL and testing question. James Kuyper <jameskuyper@verizon.net> - 2016-06-17 09:16 -0400
Re: setting pointers to NULL and testing question. Tim Rentsch <txr@alumni.caltech.edu> - 2016-06-21 11:03 -0700
Re: setting pointers to NULL and testing question. Tim Rentsch <txr@alumni.caltech.edu> - 2016-06-21 10:58 -0700
Re: setting pointers to NULL and testing question. Keith Thompson <kst-u@mib.org> - 2016-06-21 11:28 -0700
Re: setting pointers to NULL and testing question. Tim Rentsch <txr@alumni.caltech.edu> - 2016-06-16 21:39 -0700
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