use warnings;
use strict;

package Test;

sub new {
    my $class = shift;
    my $self  = {
        _DataMember0      => shift,
        _Array0           => shift,
    };
    bless $self, $class;
}
sub get__Array0{
    my $self = shift;

    if (wantarray){
        # caller wants a list (dereference the ref before return)
        return @{ $self->{_Array0} };
    }
    else {
        # caller wants an array reference
        return $self->{_Array0};
    }
}

package main;

my $aref = [1, 2, 3];

my $test = Test->new(1, $aref);

# get it as a list
my @array = $test->get__Array0(); # parens not needed, only used for clarity

# get an aref instead
my $array_reference = $test->get__Array0();

print "$_\n" for @array;
print "$array_reference->[0]\n";