How to implement Association,Aggregation and Composition in PHP?

[solutionwand]

Hi Bytes Community,

How to implement Association , aggregation and composition in php. Please explain with complete example.

<?php 

// composition and aggregation demo
class Car{
	
	function __construct() {
	   $engineObj = new Engine();
       print "In constructor >> Car <br/>";
   }

   function __destruct() {
       print "Destroying >> Car<br/> ";
   }
	
	}
class Engine{

  function __construct() {
	   
       print "In constructor >> Engine <br/>";
   }

   function __destruct() {
       print "Destroying >> Engine <br/>";
   }
}




?>

and I called this in index.php file like this.

<?php 
include('classes/objects.php');

//$engineObject = new Engine();
$carObject = new Car();

?>

its output comes.

In constructor >> Engine 
In constructor >> Car 
Destroying >> Engine 
Destroying >> Car

I have this code, but little confused.
Technically in case of COMPOSITION its out put should not be like given ?

In constructor >> Engine 
In constructor >> Car 
Destroying >> Car
Destroying >> Engine

because If car shall destroy then Engine shall destroy. Please solve this mystery.
Thanks