oop - PHP - unique attribute for objects of a class -

i have class

class myclass{     private $id;     private $name;     public function __construct ($id, $name){         $this->name = $name;     } }  $ob1 = new myclass(1, 'earth'); $ob2 = new myclass(2, 'sky'); $ob3 = new myclass(3, 'ocean'); 

i want objects $ob1, $ob2 , $ob3 have different attribute $id. example when make :

$ob4 = new myclass(3, 'wood'); 

the code denies me create object

thanks

you need keep track of ids in static class property:

class myclass {     static private $ids = [];      public function __construct($id) {         if (in_array($id, self::$ids)) {             throw new exception("object id $id constructed");         }         self::$ids[] = $id;     } } 

having said this, question usefulness of this. sounds recipe problems. should keep track of unique data part of business logic , database interaction, not enforced on language level.