Front page | perl.perl5.porters |
Postings from January 2011
On Wed, Jan 26, 2011 at 10:19 AM, Abigail <abigail@abigail.be> wrote:
> On Wed, Jan 26, 2011 at 02:22:02PM +0000, Ed Avis wrote:
>> Brad Baxter <bmb <at> mail.libs.uga.edu> writes:
>>
>> >>> perl -E '@a = ("1"); say "1 x" ~~ @a'
>>
>> >>This is a slightly unperlish distinction; usually in Perl it doesn't matter
>> >>whether a scalar holds the number 42 or the string '42'
>>
>> >Perhaps I misunderstand the example, but there is no time that I'm aware
>> >of when perl would store "1 x" in a scalar as a number.
>>
>> I was referring to this difference:
>>
>> % perl -E '@a = ("1"); say "1 x" ~~ @a'
>>
>> % perl -E '@a = (1); say "1 x" ~~ @a'
>> 1
>>
>> So you have to be aware of the difference between 1 and '1'.
>> This is the only place in everyday Perl programming where the difference is
>> noticeable.
>
>
> False, unfortunally.
>
> $ perl -wE 'say 10 | 33'
> 43
> $ perl -wE 'say "10" | "33"'
> 33
> $
>
> And it can even be more subtle:
>
> $ perl -E '$a = $b = "abc100"; 0 + $b; say $a; say $b;
> $a ++; $b ++; say $a; say $b'
> abc100
> abc100
> abc101
> 1
> $
Ah, well, I guess I stand corrected. :-)
perl -E "$a = '000'; $b = '1 x'; say $a|$b; 0 + $b; say $a|$b"
10x
1
Perl *is* storing '1 x' as a number. Very interesting.
Though I suppose "storing ... as a number" is probably
too vague a way of saying that ...
--
Brad
Thread Previous
|
Thread Next