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From: bart <bc@freeuk.com>
Newsgroups: comp.lang.c
Subject: Re: Checking the loop variable after the loop has ended (Was: Loops
 (was Re: do { quit; } else { }))
Date: Fri, 18 Apr 2025 20:10:32 +0100
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On 18/04/2025 19:33, Lew Pitcher wrote:
> On Fri, 18 Apr 2025 13:58:08 +0000, Kenny McCormack wrote:
> 
>> In article <vtrvc6$mjoi$1@dont-email.me>,
>> Lew Pitcher  <lew.pitcher@digitalfreehold.ca> wrote:
>> ...
>>>>      for (i=0; i<10; i++) { code that might or might not break }
>>>>      if (i == 10) puts("It ended normally");
>>>
>>> It's also a handy idiom for a compact list search loop
>>> where the terminating condition is either end of the list, or
>>> a matched entry.
>>> If the cursor isn't the end-of-list marker, then it references
>>> the matched entry;
>>
>> Indeed.  This is the common case - where you are looking for something, and
>> if you find it, you break out of the loop (one way or another).  If you
>> don't find it, then the loop terminates "normally" - and you need to catch
>> that case.
>>
>>>   for (n = NUM_ENTRIES; (n >= 0) && (node[n] != key); --n) continue;
>>>   if (n != -1) printf("Found key at entry %d\n",n);
>>
>> Bart won't like the way you've abused C's "for" statement syntax
> 
> I've long since stopped caring what Bart does or doesn't like. :-)

That's fine. It's been far longer that I've given up caring what people 
think of my generated C code

(They used to like turning up the warnings high enough for it to fail. 
Clearly that defined but unused label is a critical error.)

> 
> 
>> to your own devious ends...
> 
> 
> I'll give you another devious one :-)
> 
>    #include <stdio.h>
>    #include <stdlib.h>
>    int main(void)
>    {
>      double nc;
> 
>      for (nc = 0; getchar() != EOF; ++nc)
>        ;
> 
>      printf("%.0f\n",nc);

I'll give you this one. Finally something that is impossible to achieve 
with a simple and far more appropriate 'while':

     double nc;

     nc = 0;
     while (getchar() != EOF) ++nc;

     printf("%.0f\n",nc);


> As do I. It is succinct, complies with the syntax of the C language,
> and achieves the desired algorithmic goal.

That's a pretty low bar. You can say the same about any of my generated, 
low-level C code, which is pretty much unreadable by any human.

It's odd how some here have standards which stops them even declaring 
three related variables on the same line:

     double x, y, z;         // fails guidelines

But cramming as much crap as possible into a FOR-loop header, for no 
reason other than because you can, seems to be condoned.