PHP对象克隆clone用法示例
author:一佰互联 2019-04-26   click:168

本文实例讲述了PHP对象克隆clone用法。分享给大家供大家参考,具体如下:

浅克隆:只是克隆对象中的非对象非资源数据,即对象中属性存储的是对象类型,则会出现克隆不完全

<?php
class B{
 public $val = 10;
}
class A{
 public $val = 20;
 public $b;
 public function __construct(){
  $this->b = new B();
 }
}
$obj_a = new A();
$obj_b = clone $obj_a;
$obj_a->val = 30;
$obj_a->b->val = 40;
var_dump($obj_a);
echo "<br>";
var_dump($obj_b);

运行结果如下:

object(A)[1]
 public "val" => int 30
 public "b" => 
 object(B)[2]
  public "val" => int 40

object(A)[3]
 public "val" => int 20
 public "b" => 
 object(B)[2]
  public "val" => int 40

深克隆:一个对象的所有属性数据都彻底的复制,需要使用魔术方法__clone(),并在里面实现深度克隆

<?php
class B{
 public $val = 10;
}
class A{
 public $val = 20;
 public $b;
 public function __construct(){
  $this->b = new B();
 }
 public function __clone(){
  $this->b = clone $this->b;
 }
}
$obj_a = new A();
$obj_b = clone $obj_a;
$obj_a->val = 30;
$obj_a->b->val = 40;
var_dump($obj_a);
echo "<br>";
var_dump($obj_b);

运行结果如下:

object(A)[1]
 public "val" => int 30
 public "b" => 
 object(B)[2]
  public "val" => int 40

object(A)[3]
 public "val" => int 20
 public "b" => 
 object(B)[4]
  public "val" => int 10

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