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Re: Reassigning variable to new object destroys old one?

Posted by Toby A Inkster on 04/30/07 16:40

ZeldorBlat wrote:

> The object is automatically destroyed when nothing is referencing it.
> When you assign the second instance to $x, there is nothing left
> referencing the first instance.

This isn't strictly true. There may still be other references to the
object floating about.

class Foo
{
public static $primary_instance = NULL;
public $val;

public function __construct ($n)
{
if (!isset(self::$primary_instance))
self::$primary_instance = $this;
$this->val = $n;
}

public function carp ()
{
echo $this->val . "\n";
}
}

$x = new Foo(123); // First Foo object

$x = new Foo(456); // Replacement Foo object
$x->carp();

// But the first one is still hanging around
// because another reference to it exists.
Foo::$primary_instance->carp();

--
Toby A Inkster BSc (Hons) ARCS
http://tobyinkster.co.uk/
Geek of ~ HTML/SQL/Perl/PHP/Python/Apache/Linux

 

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