gistfile1.php

<?php

class Foo{

   protected $bar;

   /** @var Lol[] */
   protected $lols=array();

   public function setBar(Bar $bar){
      $this->bar=$bar;
   }

   public function getBar(){
      return $this->bar;
   }

   public function addLol(Lol $lol){
      $this->lols[]=$lol;
   }

   /**
    * @return Lol[]
    */
   public function getAllLols(){
      return $this->lols;
   }

}

class Bar{

   protected $id;

   public function setID($id){
      $this->id=$id;
   }

}

class Lol{

   protected $name;

   /** @var  Bar */
   protected $bar;

   public function setBar(Bar $bar){
      $this->bar=$bar;
   }

   public function getBar(){
      return $this->bar;
   }

   public function setName($name) {
      $this->name = $name;
   }

   public function getName() {
      return $this->name;
   }

}

$bar=new Bar();
$bar->setID(1);

var_dump($bar);
         // object(Bar)[1]
         //   protected 'id' => int 1


$foo=new Foo();
$foo->setBar($bar);
$bar->setID(3);

var_dump($foo);
         //   object(Foo)[2]
         //     protected 'bar' =>
         //       object(Bar)[1]
         //         protected 'id' => int 3
         //     protected 'lols' =>
         //       array (size=0)
         //         empty
var_dump($bar);
         //   object(Bar)[1]
         //     protected 'id' => int 3
var_dump($bar===$foo->getBar());
         //   boolean true


$newFoo=new Foo();
for($i=1; $i<5; $i++){
   $newlol=new Lol();
   $newbar=new Bar();
   $newbar->setID($i);
   $newlol->setBar($newbar);
   $newFoo->addLol($newlol);

}

var_dump($newFoo);
         //   object(Foo)[3]
         //     protected 'bar' => null
         //     protected 'lols' =>
         //       array (size=4)
         //         0 =>
         //           object(Lol)[4]
         //             protected 'name' => null
         //             protected 'bar' =>
         //               object(Bar)[5]
         //                 protected 'id' => int 1
         //         1 =>
         //           object(Lol)[6]
         //             protected 'name' => null
         //             protected 'bar' =>
         //               object(Bar)[7]
         //                 protected 'id' => int 2
         //         2 =>
         //           object(Lol)[8]
         //             protected 'name' => null
         //             protected 'bar' =>
         //               object(Bar)[9]
         //                 protected 'id' => int 3
         //         3 =>
         //           object(Lol)[10]
         //             protected 'name' => null
         //             protected 'bar' =>
         //               object(Bar)[11]
         //                 protected 'id' => int 4
$copyFoo = $newFoo;
$newID=10;
foreach($newFoo->getAllLols() as $lol){
   $lol->getBar()->setID($newID++);
   $lol->setName('bla');
}
var_dump($newFoo);
         //   object(Foo)[3]
         //     protected 'bar' => null
         //     protected 'lols' =>
         //       array (size=4)
         //         0 =>
         //           object(Lol)[4]
         //             protected 'name' => string 'bla' (length=3)
         //             protected 'bar' =>
         //               object(Bar)[5]
         //                 protected 'id' => int 10
         //         1 =>
         //           object(Lol)[6]
         //             protected 'name' => string 'bla' (length=3)
         //             protected 'bar' =>
         //               object(Bar)[7]
         //                 protected 'id' => int 11
         //         2 =>
         //           object(Lol)[8]
         //             protected 'name' => string 'bla' (length=3)
         //             protected 'bar' =>
         //               object(Bar)[9]
         //                 protected 'id' => int 12
         //         3 =>
         //           object(Lol)[10]
         //             protected 'name' => string 'bla' (length=3)
         //             protected 'bar' =>
         //               object(Bar)[11]
         //                 protected 'id' => int 13

var_dump($copyFoo);
         //   object(Foo)[3]
         //     protected 'bar' => null
         //     protected 'lols' =>
         //       array (size=4)
         //         0 =>
         //           object(Lol)[4]
         //             protected 'name' => string 'bla' (length=3)
         //             protected 'bar' =>
         //               object(Bar)[5]
         //                 protected 'id' => int 10
         //         1 =>
         //           object(Lol)[6]
         //             protected 'name' => string 'bla' (length=3)
         //             protected 'bar' =>
         //               object(Bar)[7]
         //                 protected 'id' => int 11
         //         2 =>
         //           object(Lol)[8]
         //             protected 'name' => string 'bla' (length=3)
         //             protected 'bar' =>
         //               object(Bar)[9]
         //                 protected 'id' => int 12
         //         3 =>
         //           object(Lol)[10]
         //             protected 'name' => string 'bla' (length=3)
         //             protected 'bar' =>
         //               object(Bar)[11]
         //                 protected 'id' => int 13

var_dump($newFoo===$copyFoo);
         //   boolean true