Kaedah __clone

Kaedah __clone dipanggil secara automatik apabila menggunakan operator clone. Ia membolehkan anda menentukan logik penyalinan objek sendiri. Secara lalai, PHP melakukan penyalinan cetusan semua sifat objek. Kaedah __clone berguna apabila perlu melaksanakan penyalinan mendalam atau mengubah tingkah laku semasa pengklonan.

Sintaks

public function __clone(): void

Contoh

Laksanakan pengklonan objek asas:

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

Keputusan pelaksanaan kod:

'Objek diklon'

Contoh

Laksanakan penyalinan mendalam objek dengan objek bersarang:

<?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;
?>

Keputusan pelaksanaan kod:

'New York'

Contoh

Tambahkan pengecam unik semasa pengklonan:

<?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;
?>

Keputusan pelaksanaan kod (contoh):

'5f1a2b3c 5f1a2b3d'

Lihat juga

kaedah __construct,
yang merupakan pembina objek