sub test {
   my $scalar1 = shift;
   my $array2_ref = shift;
   my $hash3_ref = shift;

   ### if you want to work with the hash, and not just
   ### the hash reference, then dereference the ref.
   my %hash3 = %$hash3_ref;
   print "value for hash key 'one' is $hash3{'one'}\n";

   ### I prefer to just use the reference instead, and
   ### not create the hash by dereferencing the hash ref.
   print "value for hash key 'one' is $hash3_ref->{'one'}\n";
   return($scalar1, $array2_ref, $hash3_ref);
}

my $test_scalar = "abc";
my @test_array = ( "a", "b", "c" );
my %test_hash = ( "a" => 1,
                  "b" => 2,
                  "c" => 3 );
($new_scalar, $new_arrayref, $new_hashref) = test($test_scalar, \@test_array, \%test_hash);