sub new
     {
     #Arg0 is the type because the constructor will look like
     #  my($instance) = Tree->new(arg1,arg2,whatever)
     #so arg0 will be Tree.
     my($type) = $_[0];

     #Make subroutine-local var $self, and make it a reference.
     #Specifically, make it a reference to a (right now) empty hash.
     #Later on, that hash will contain object properties.
     my($self) = {};

     #For now, we'll have one instance variable (property, whatever)
     #It will be in the hash referenced by $self, and will have
     #the index 'root'. This will be the first arg (inside the parentheses)
     #of the call to the constructor in the main program.
     $self->{'root'} = $_[1];    #remember $_[0] was the Tree before the ->

     #There's nothing reserved about the word $self. It could have been
     #called $oodolaboodola. To link the object with both the hash pointed
     #to by $self and the type (Tree), we use the 2 argument version
     #of the keyword bless:
     bless($self, $type);

     #Now finally, return the hash as a reference to be used as an "object"
     return($self);
     }

package MyMysql;

use strict;
use DBI;

sub new { 
    my $class = shift;
    my $self = {}
    my $self->{db}         = "mydatabase";
    my $self->{host}       = "localhost";
    my $self->{user}       = "root";
    my $self->{dsn}        = "DBI:mysql:$db:$host";
    my $self->{attributes} = { PrintError => 0, RaiseError => 0 };
    return bless $self, $class;}

sub add_user(){
    my $self=shift;
    my $self->{nickname}  =$_[0];
    my $self->{password}  =$_[1];
    my $self->{firstname} =$_[2];
    my $self->{name}      =$_[3];
    my $self->{gender}    =$_[4];
    my $self->{birthdate} =$_[5];
    my $self->{dbh} = DBI->connect($self->{dsn},$self->{user},undef,
       $self->{attributes}) or
       $self->WriteError('',"Error in connecting to $self->{dsn}", die => 1); )
$self->{nickname} = $dbh->quote($self->{nickname});
$slef->{password} = $dbh->quote($self->{password});}

subb add_user{
  my ($self,@data) = @_;
  my $i = 0;
  for(qw/nickname password firstname name gender birthday/){
    $self->{$_} = $dbh->quote($data[$i]);
    ++$i;
  }
  # connect;
}

my $object = bless([
  "vorname",
  "nachname",
  4.4.1944,
], "Meine::Klasse");