$Bill Luebkert wrote:
> Bowie Bailey wrote:
> > [EMAIL PROTECTED] wrote:
> >
> > > Er, aren't hash keys interpreted as strings, even if they contain
> > > digits?
> >
> > Perl does not have a strict distinction between string and numeric
> > data. They are both considered scalars. The difference comes in
> > how you use the scalar value.
> >
> > Try this:
> >
> > $a = "10";
> > $b = "2";
>
> You can get around this by using fixed length numerics if you for
> example want to intermix them with non-numeric strings and still have
> them sort:
Yes, but the question wasn't about how to make it work, the question
was about the difference. The post I originally replied to got it's
numbers by counting occurrences of words.
> my $a = sprintf '%04u', 10; # assuming 4 digits max
> my $b = sprintf '%04u', 2;
Or just:
my $a = "0010";
my $b = "0002";
> Then you can sort them using string compares and mix them in with your
> other strings. Let's not get into what happens when a string has
> alpha and numerics in it (unless of course they're fixed in position
> - eg: abcd0001).
You can do that as long as you don't do any numeric operations on
them.
> A prime example of comparing numbers as strings would be dates. If
> you specify a date as YYYYMMDD (or DDMMYYYY), you can easily sort
> them with a string compare and is a good way to store dates if binary
> epoch time isn't an option.
Actually, this is a case where it doesn't matter which one you use.
The digits are fixed, so they sort the same either way.
You would need a string comparison if your format was YYYY-MM-DD.
But this is all just an interesting side note. What it comes down to
(unless you have some special circumstances) is this:
- If your data is numeric, use numeric comparisons.
- If your data contains other characters, use string comparisons (and
watch your formatting carefully).
--
Bowie
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