From: Roman Makurin <dro...@gmail.com>
> here is complite perl script which produces such results without
> any warning:
>
> #!/usr/bin/perl
>
> use strict;
> use warnings;
>
> use constant {
> A => 0,
> B => 1,
> C => 2 };
>
> my @a = (A, B, C);
> my @b = (1, 2, 3);
>
> while(my $i = shift @a) {
> print $i, $/
> }
But of course this does not print anything. The shift(@a) returns the
first element of @a which is zero, assigns that to $i and then checks
whether it's true. And of course it's not. So it skips the body and
leaves the loop. Keep in mind that the value of
my $i = shift @a
is NOT a true/false whether there was something shifted from the
array. It's the value that was removed from the array and assigned to
the $i. And if that value it false (undef, 0, 0.0, "0", "0.0", "" -
if I remember rigth) then the whole expression evaluates to false in
boolean context.
Whether you use constants or not is irrelevant. You'd see the same
behaviour with
my @a = (0, 1, 2);
HTH, Jenda
===== je...@krynicky.cz === http://Jenda.Krynicky.cz =====
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