Re: [Boston.pm] something about @_ is different?

Assigning to @_ is weird and I don't recommend it. It's full of magic
aliases, which in some cases means you change the caller's variables, which
is usually not what you want.

Check the beginning of perldoc perlsub.

On Tue, May 21, 2019, 2:04 PM Greg London <email-2Ro/Dj86MvDSUeElwK9/[email protected]> wrote:

>
> Hm, it could be a caffeine defficiency, but it seems that @_ is
> being treated different than other arrays.
>
> I can create a normal array:
> my @normal_array=('a','b');
>
> and I can assign an entirely new list to it:
> @normal_array=reverse(@normal_array);     # assign to array
>
> and I can assign to it in parenthesis an entirely new list
> (@normal_array)=reverse(@normal_array);   # assign to (array)
>
>
> And those assignements take hold as I would expect.
>
> When I use the exact same syntax for the @_ array instead
> of @normal_array, it doesn't work as expected:
> sub swapper{
>         (@_) = reverse(@_);  # this doesn't seem to do anything.
> }
>
> my @other=('x','y');
> swapper(@other);
> print Dumper \@other;
>
> Pretty sure this code used to work,
> but that was many moons ago.
>
> Thoughts?
>
> Greg
>
> Here's the script in one big copy/paste block:
>
>
> my @normal_array=('a','b');
> print "normal_array is "; print Dumper \@normal_array;
> @normal_array=reverse(@normal_array);     # assign to array
> print "normal_array is "; print Dumper \@normal_array;
> (@normal_array)=reverse(@normal_array);   # assign to (array)
> print "normal_array is "; print Dumper \@normal_array;
>
>
> sub swapper{
>         (@_) = reverse(@_);
> }
>
> my $one = "i am one";
> my $two = "i am two";
>
> swapper($one,$two);
>
> warn "one is '$one'";
> warn "two is '$two'";
>
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