PHP物件克隆clone用法範例

本文實例講述了PHP物件克隆clone用法。分享給大家供大家參考，如下：

淺克隆：只是克隆對像中的非對象非資源數據，即對像中屬性存儲的是對象類型，則會出現克隆不完全

<?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 &#39;<br>&#39;;
var_dump($obj_b);

結果如下：

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：一個物件的所有屬性資料都徹底的複製，需要使用魔術方法__clone()，並在裡面實現深度克隆

<?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 &#39;<br>&#39;;
var_dump($obj_b);

   

 

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

   

希望本文所述對大家PHP程式設計有所幫助。

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