Re: Passing different values into subroutines

I have got in to trouble before trying to pass multiple parms to a subroutine that are not scalars. I believe that perl internally concatenates all parameters into a single array.

As others have suggested, use references. To call a subroutine, I use:

thisIsMySub( \@onearray, \%ahasd, \@secondarray, $scalar1, $scalar2);
[download]

And in the subroutine itself, I use:

my @firstarray   = @{shift };
my %somehash     = %{shift };
my @secondadrray = @{shift };
my $scalarone    =   shift;
my $scalartwo    =   shift;
[download]

I would gladly accept advice from others if there is a better way to do this.

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RE: Re: Passing different values into subroutines by chromatic (Archbishop) on Sep 01, 2000 at 08:37 UTC
I believe that perl internally concatenates all parameters into a single array. Very close. Parameters are passed as a list. When you assign something to a list, there's no way for Perl to know how long the list is supposed to be, so it slurps up everything available. It's kinda like the greedy * operator that's come under fire recently (Death to Dot Star). If you need to get more than one list (whether list, array, or hash) to or from a subroutine, you need to use a reference, otherwise they'll blend together like a creamy fruit smoothie. Codewise, sometimes I explicitly dereference-and-copy my arguments like you do, and sometimes I just act on them directly: `my $arr_ref = shift; foreach my $item (@$arr_ref) { $item .= "foo"; }` [download]	[reply] [d/l]

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RE: Re: Passing different values into subroutines
by chromatic (Archbishop) on Sep 01, 2000 at 08:37 UTC

I believe that perl internally concatenates all parameters into a single array.

Very close. Parameters are passed as a list. When you assign something to a list, there's no way for Perl to know how long the list is supposed to be, so it slurps up everything available. It's kinda like the greedy * operator that's come under fire recently (Death to Dot Star).

If you need to get more than one list (whether list, array, or hash) to or from a subroutine, you need to use a reference, otherwise they'll blend together like a creamy fruit smoothie.

Codewise, sometimes I explicitly dereference-and-copy my arguments like you do, and sometimes I just act on them directly:

my $arr_ref = shift;
foreach my $item (@$arr_ref) {
    $item .= "foo";
}
[download]

[reply]
[d/l]