#!/usr/bin/perl

use strict;
use warnings;

my %hash=();
my $hlen = get_infos(\%hash);
print "hlen: $hlen\n";
print("Hallo " . $hash{"hallo"}->[0] . "\n");

sub get_infos {
    my ($hash) = @_;
    my $key = "hallo";
    my $irgendwas = "Welt";

    push(@{$hash->{$key}},$irgendwas);
    return keys %$hash;
}