#!/usr/bin/perl

use warnings;
use strict;

my $scalar = 'EINS';
my @array  = qw(eins zwei drei);
my %hash   = ('eins' => '1', 'zwei' => '2');

test_sub(\$scalar,\@array,\%hash);

sub test_sub {

   my $scalarref = shift;
   my $arrayref  = shift;
   my $hashref   = shift;

   print 'SCALARREF....', $$scalarref.'HALLO', "\n";
   print 'ARRAYREF.....', @$arrayref,          "\n";
   print 'ARRAYREF_1...', $$arrayref[0],       "\n";
   print 'ARRAYREF_1...', ${$arrayref}[0],     "\n";
   print 'ARRAYREF_1...', $arrayref->[0],      "\n";
   print 'HASHREF......', keys %$hashref,      "\n";
   print 'HASHREF_1....', $$hashref{'zwei'},   "\n";
   print 'HASHREF_1....', ${$hashref}{'zwei'}, "\n";
   print 'HASHREF_1....', $hashref->{'zwei'},  "\n";

} # test_sub