package Stats;
use strict;
use warnings;
use Carp qw/croak/;

sub new {
  ref (my $class = shift) && croak 'class name needed in constructor';
  my $self = {@_};
  bless $self, $class;
}

sub alive {
  my $self = shift;
  for (my ($k, $v) = each(%$self) ) {
    print "$k has the value $v\n";
  }
}
1;

perl -MStats -e '$x = Stats->new(-test => 'bla', -test2 => 'blubb'); $x->alive();'

-test2 has the value blubb
-test2 has the value blubb

-test has the value bla
-test2 has the value blubb

$ perl -wle'
my %h = (a => 23, b => 24, c => 25);
print "while";
while (my ($k, $v) = each %h) {
  print "$k => $v";
}
print "for";
for (my ($k, $v) = each %h) {
  print "$k => $v";
}
'
while
c => 25
a => 23
b => 24
for
c => 25
c => 25