note 36028 added to language.references
| From: | sieglt at unreal64 dot net | Date: | Tue, 23 Sep 2003 12:51:05 +0000 |
| Subject: | note 36028 added to language.references | ||
| Groups: | php.notes | ||
| Request: | Send a blank email to php-notes+get-56972@lists.php.net to get a copy of this message | ||
Strange references behaviour when using objects.
Here is a simple example how to get reference to an object which is referenced by other object by
calling method. You can see that GetItem2 method has argument passed by reference. You will obtain
copy of the original object not reference to the original object. The only right way what i have
discovered is using fuction returning reference. See &GetItem.
Will php5 solve this problem?
<?
class A {
var $item;
function A(&$b) {
$this->item=&$b;
}
function &GetItem() {
return($this->item);
}
function GetItem2(&$Dst) {
$Dst=$this->item;
}
};
class B {
var $value;
function SetVal($val) {
$this->value=$val;
}
function PrintMe() {
print $this->value;
print "\n";
}
};
$original=&new B();
$original->SetVal(20);
$original->PrintMe(); // prints 20
$ref=&new A($original);
$newref=&$ref->GetItem();
$newref->SetVal(30);
$original->PrintMe(); // prints 30
unset($newref2);
$ref->GetItem2($newref2);
$newref2->SetVal(40);
$original->PrintMe(); // prints 30 NOT 40 !!!
?>
----
Manual Page -- http://www.php.net/manual/en/language.references.php
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