On Tue Sep 22 2009 @ 10:56, Chas. Owens wrote:
> On Tue, Sep 22, 2009 at 09:40, Bryan R Harris
> <bryan_r_har...@raytheon.com> wrote:
> > Can you explain how perl interprets this? I would've incorrectly thought:
> >
> > 1) "() = func_that_return_list_value" tries to assign the list to "()"
> > which perl would complain about.
> >
> > 2) Then assign the result to $size, which it wouldn't like either.
> >
> > Just when you think you're starting to understand perl...
> snip
>
> The number of "catcher" elements in a list does not need to be equal
> to the number of "thrown" items:
>
> my ($x, $y) = (1, 2, 3);
>
> List assignment behaves differently in list and scalar contexts. In
> list context, it returns the list that was successfully assigned to
> variables. In scalar context, it returns the number of items that
> tried to be assigned. So, in
>
> perl -le '$z = ($x, $y) = (qw/a b c/); print "$x, $y, $z"'
>
> $z is 3 (because there were three items in RHS of the assignment), $x
> is "a", and $y is "b". "c" is silently discarded.
All of this makes sense, but I have to admit I find it odd that the
following doesn't even produce a "void context" warning:
my @array = (1, 2, 3);
my $num = () = @array;
print $num, "\n";
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