This is to show the affect of changing property of object A through another object B when you pass object A as a property of another object B.

<?php
 // data class to be passed to another class as an object
 class A{
     public $info;
    function __construct(){
        $this->info = "eeee";
    }
 }
 
 // B class to change the info in A obj
 class B_class{
     public $A_obj;
    
    function __construct($A_obj){
        $this->A_obj =  $A_obj;
    }
    public function change($newVal){
        $this->A_obj->info = $newVal;
    }
 }

 // create data object from the A
 $A_obj = new A();
 // print the info property
 echo 'A_obj info: ' . $A_obj->info . '<br/>';
 
 // create the B object and pass the A_obj we created above
 $B_obj = new B_class($A_obj);
 // print the info property through the B object to make sure it has the same value 'eeee'
 echo 'B_obj info: ' . $B_obj->A_obj->info . '<br/>';
 
 // chage the info property
 $B_obj->change('xxxxx');
 // print the info property through the B object to make sure it changed the value to 'xxxxxx'
 echo 'B_obj info after change: ' . $B_obj->A_obj->info . '<br/>';
 // print the info property from the A_obj to see if the change through B_obj has affected it
 echo 'A_obj info: ' . $A_obj->info . '<br/>';

?>

The result:

A_obj info: eeee
B_obj info: eeee
B_obj info after change: xxxxx
A_obj info: xxxxx