C++ Scope

[Jonathan Clements]

Hi all,

Does 'for' have it's own scope? In one compiler I'm quite happy
writing:-

for(unsigned long i=1; i <= WHATEVER; i++) { /* something here */ } and
then (not nested)
for(unsigned long i=1; i <= WHATEVER2; i++) { /* something here2 */ }

Probably bad practice, but as far as I understand C++, 'i' should be a
temp within the scope of the for loop. Some compilers allow this, others
don't.... I'm wondering if I'm mis-understanding the scope rules or the
compilers are.

Thanks,

Jon.

[Kurt Krueckeberg]

Re: C++ Scope

[color=blue]
> Hi all,
>
> Does 'for' have it's own scope? In one compiler I'm quite happy
> writing:-
>
> for(unsigned long i=1; i <= WHATEVER; i++) { /* something here */ }[/color]
and[color=blue]
> then (not nested)
> for(unsigned long i=1; i <= WHATEVER2; i++) { /* something here2 */ }
>
> Probably bad practice, but as far as I understand C++, 'i' should be a
> temp within the scope of the for loop. Some compilers allow this, others
> don't.... I'm wondering if I'm mis-understanding the scope rules or the
> compilers are.
>[/color]
Your code is correct, even if some compilers incorrectly complain.

[Stuart Golodetz]

Re: C++ Scope

"Jonathan Clements" <jonathan@psilo cybe.demon.co.u k> wrote in message
news:bdnanh$lv7 $1$8302bc10@new s.demon.co.uk.. .[color=blue]
> Hi all,
>
> Does 'for' have it's own scope? In one compiler I'm quite happy
> writing:-
>
> for(unsigned long i=1; i <= WHATEVER; i++) { /* something here */ }[/color]
and[color=blue]
> then (not nested)
> for(unsigned long i=1; i <= WHATEVER2; i++) { /* something here2 */ }
>
> Probably bad practice, but as far as I understand C++, 'i' should be a
> temp within the scope of the for loop. Some compilers allow this, others
> don't.... I'm wondering if I'm mis-understanding the scope rules or the
> compilers are.[/color]

The compilers are. It's perfectly good (and common) practice to reuse loop
variables like i. If one of your compilers doesn't like it, just put:

#define for if(0); else for

at the top of each translation unit and it'll fix it.

HTH,

Stuart.
[color=blue]
> Thanks,
>
> Jon.[/color]

[Jonathan Clements]

Re: C++ Scope

Thank you to Kurt K., John H., and Stuart G. for your replies...

"Jonathan Clements" <jonathan@psilo cybe.demon.co.u k> wrote in message
news:bdnanh$lv7 $1$8302bc10@new s.demon.co.uk.. .[color=blue]
> Hi all,
>
> Does 'for' have it's own scope? In one compiler I'm quite happy
> writing:-
>
> for(unsigned long i=1; i <= WHATEVER; i++) { /* something here */ }[/color]
and[color=blue]
> then (not nested)
> for(unsigned long i=1; i <= WHATEVER2; i++) { /* something here2 */ }
>
> Probably bad practice, but as far as I understand C++, 'i' should be a
> temp within the scope of the for loop. Some compilers allow this, others
> don't.... I'm wondering if I'm mis-understanding the scope rules or the
> compilers are.
>
> Thanks,
>
> Jon.
>
>
>
>[/color]