class Pracownik { 
   static public $NastepnyID = 1; 
   public $ID; 
   public function __construct() { 
      $this->ID = self::$NastepnyID++; 
   } 
   public function NastepnyID() { 
      return self::$NastepnyID; 
   } 
} 
$bartek = new Pracownik; 
$jan = new Pracownik; 
$szymon = new Pracownik; 
print $bartek->ID . "\n"; 
print $jan->ID . "\n"; 
print $szymon->ID . "\n"; 
print Pracownik::$NastepnyID . "\n"; 
print Pracownik::NastepnyID() . "\n"; 
