our $references;

##</code><code>##

my @references;

# -- inside new()
   push @references, $objref;

#
#.. inside sub test() ..
#
    foreach my $object(@references){ ....}

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;

package User;
 # our @references;

  sub new {
      my ($class, %arg) = @_;
      my $self = {
          _name                   => $arg{name}    || "unknown"
         ,_team                   => $arg{team}    || "unknown"
      };
      bless $self, $class;

      #push @references, $self;
      my ($team) = Team->find($arg{team}) ;
      $arg{team} and ( $team ||= Team->new($arg{team}) );

      $team and $team->AddUser($self);

      return $self;
  }
  sub name{ # Accessor
      $_[0]->{_name};
  }
  sub List_Opponents {
      my $self = shift @_;
      my $myTeam = Team->find(  $self->{_team}  );
      foreach my $T (Team->GetTeamList()) {
          next if $self->{_team} eq $T->{name};
         #find opposing team
         #do something to $T
         print " " . $self->name . "\ton $self->{_team} vs. " .
            "\tmembers of $T->{name} \n";
      }
  }
  sub getUserByName{
      my ($self, $lookfor) = @_;
      my @Users;
      foreach my $t (Team->GetTeamList()) {
          # next if $self->{_team} eq $t->{name};
          push @Users, grep {$_->name eq $lookfor} $t->GetUserList;
      }
      return @Users
  }
########################################
package Team;
  my @TeamList;
  sub new{
      my ($class, $name) = @_;
      my $self = {name=>$name};
      bless $self, $class;
      push @TeamList, $self;
      return $self;
  }
  sub AddUser{ #By Object
      my $self = shift;
      while (local $_=shift){    # $_ contains the NAME of the user to add
        my $userTeam= findUserObj ($self, $_); # Look for This userobj
        if ($userTeam){
           $userTeam == $self and next; # is already there in this list. dont add again
           warn "*** User " . $_->name . " is already in team $userTeam->{name}.
           Now also added to $self->{name}\n";
         }
        push @{$self->{userlist}},$_;
      }
  }
  sub CreateAndAddUser{
      my ($self, @UserNames) = @_;
      AddUser($self, map {User->new(name => $_, team=> $self->{name})} @UserNames  );
  }
  sub GetUserList{
      my $self = shift;
      return () unless exists $self->{userlist} ;
      return (  @{$self->{userlist}} );
  }
  sub find{ #Return Team object (or undef) given team NAME.
      my $self = shift;
      my $lookfor = shift || $self; # In case CLASS method is called.
      for my $t(@TeamList){
        return  $t if $t->{name} eq $lookfor;
      }
      return undef;
  }
  sub findUserObj{
      my ($self, $UserObj) = @_;
      for my $t (@TeamList){
        return $t if  grep {$_ == $UserObj} GetUserList($t) ;
      }
      return undef;
  }
  sub GetTeamList{
     return @TeamList;
  }
##############################################
package main;

my $t1 = Team->new ("MyTeam");
my $t2 = Team->new ("OtherTeam");
my $SingleUser = User->new(name => "OneSingleUser", team=> "teamBeta");
my @testUsers = (
   (map { User->new(name => "user$_", team=> "teamalpha")}  0..4),
   (map { User->new(name => "user$_", team=> "teamBeta") }  5..9)  );

   #Cread Anon Team object (which we can find later)
Team->new("Planets")->CreateAndAddUser(  qw /mercury venus earth mars jupiter /);

$t1->AddUser (@testUsers[0,1,2] );
$t2->AddUser (@testUsers[3,5,6] );
$t1->CreateAndAddUser(  qw /foo bar baz quux  /);
$t2->CreateAndAddUser(  qw /Ahmed sohrab rustom quasim /);
Team->find("Planets")->CreateAndAddUser(  qw /saturn Asteroids pluto/);
$testUsers[0]->List_Opponents();
$testUsers[5]->List_Opponents();
$SingleUser->List_Opponents();

for my $t (Team->GetTeamList()){
   print "---Team: $t->{name} -----\n";
   print "  " . $_->name . "\n" for $t->GetUserList;
}