Jan Eden wrote:
>
> Rob, I read the perlfaq paragraph you mentioned and found that it proposes a
> solution which does not make use of 'exists':
>
> @blues = qw/azure cerulean teal turquoise lapis-lazuli/;
> %is_blue = ();
> for (@blues) { $is_blue{$_} = 1 }
It's not for me to rewrite the docs (or perhaps it is?) but
for (@blues) { $is_blue{$_} = 1 }
does the same thing as
@[EMAIL PROTECTED] = (1) x @blues;
but (I would guess) the former is slower because it has a source-level loop.
That means that it's the equivalent to
@[EMAIL PROTECTED] = ();
(which the parallel to my code) except that the value for each hash
element is '1' instead of 'undef', which means that you could write
the tidier
if ($is_blue{$_})
instead of
if (exists $is_blue{$_})
> Now, I had the idea to combine your hash slice with this solution doing:
>
> @blues = qw/azure cerulean teal turquoise lapis-lazuli/;
> @[EMAIL PROTECTED] = 1;
>
> But since I have only a single number on the right side of the assignment
> function, only one hash element gets 1. Is there a way to automatically assign
> "1" to all elements with the hash slice notation (i.e. without using a loop)?
I think I just showed you that before you asked. You need as many '1's as there
are hash elements, so you need to assign 'scalar @blues' copies of the list '(1)'.
@[EMAIL PROTECTED] = (1) x @blues
> I promise to drop the subject after this question. ;)
Believe me, we're really having fun thinking around your ideas: it's better
than working for a living :) While you're learning, please keep asking.
Rob
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
<http://learn.perl.org/> <http://learn.perl.org/first-response>
