The __clone Method

The __clone method is automatically called when using the clone operator. It allows you to define custom copying logic for the object. By default, PHP performs shallow copying of all object properties. The __clone method is useful when you need to implement deep copying or change the behavior during cloning.

Syntax

public function __clone(): void

Example

Let's implement basic object cloning:

<?php
	class User {
		public $name;
		
		public function __construct($name) {
			$this->name = $name;
		}
		
		public function __clone() {
			echo 'Object cloned';
		}
	}
	
	$user1 = new User('John');
	$user2 = clone $user1;
?>

Code execution result:

'Object cloned'

Example

Let's implement deep copying of an object with nested objects:

<?php
	class Address {
		public $city;
		
		public function __construct($city) {
			$this->city = $city;
		}
	}
	
	class User {
		public $name;
		public $address;
		
		public function __construct($name, $city) {
			$this->name = $name;
			$this->address = new Address($city);
		}
		
		public function __clone() {
			$this->address = clone $this->address;
		}
	}
	
	$user1 = new User('John', 'New York');
	$user2 = clone $user1;
	$user2->address->city = 'Boston';
	
	echo $user1->address->city;
?>

Code execution result:

'New York'

Example

Let's add a unique identifier when cloning:

<?php
	class Product {
		public $id;
		public $name;
		
		public function __construct($name) {
			$this->id = uniqid();
			$this->name = $name;
		}
		
		public function __clone() {
			$this->id = uniqid();
		}
	}
	
	$product1 = new Product('Laptop');
	$product2 = clone $product1;
	
	echo $product1->id . ' ' . $product2->id;
?>

Code execution result (example):

'5f1a2b3c 5f1a2b3d'

The __clone Method

Syntax

Example

Example

Example

See Also