return \@array or @array

[Joel Bernstein]

You're wrong. Where you're going wrong is assuming that "return @foo" is
going to "return an array". It returns a list of values, the same list that
the array held in the subroutine scope.

That is:

sub foo {
  my @foo = 1..100;
  return @foo;
}

sub bar {
  my @bar = 1..100;
  return \@bar;
}

foo() will return a list of 99 elements.
bar() will return a list of 1 element, which is a reference to an array
containing 99 elements.

Does that make more sense?

/joel


On 12 September 2013 16:02, Jérôme Étévé <jerome.eteve at gmail.com> wrote:

> Hi all,
>
> I reckon there's a popular belief going around that A is "faster" than B
>
> sub fA{ ... ; return \@array; }
> sub fB{ ... ; return @array; }
>
> foreach my $thing ( @{fa()} ){ ... }
> foreach my $thing ( fB() ){ ... }
>
> My almost blind faith in the Perl internals gives me the gut feeling
> that as arrays are a very native Type in Perl, and the underlying AV
> holds a reference anyway (at the end of the day, it's C..), it
> shouldn't make much difference.
>
> And that building a Perl reference of something that's already a C
> space reference isn't going to help much.
>
> Any insight?
>
> Cheers,
>
> Jerome.
>
> --
> Jerome Eteve
> +44(0)7738864546
> http://www.eteve.net/
>
>