# this...
  my $self = {} ;
  # ... is the same of:
  my %foo ;
  my $self = \%foo ;

##</code><code>##

  my @hold_ref ;
  for(1..3) {
    my $hash_ref = {} ;
    push(@hold_ref , $hash_ref) ;
    print "$hash_ref\n" ;
  }

##</code><code>##

HASH(0x1a7f10c)
HASH(0x1a7f130)
HASH(0x1a75468)