$ref1 = $obj1; // $ref1 is a link to obj1

If we follow the manual strictly, we??™ll see that both $ref1 and $obj1 are links to the same content. After  $ref2 = $ref1 another link to the same content should be added.

Thus after $ref1 = $obj2 all three links should indicate to $obj2.

In the manual it is written that links in PHP are different from indicators in C. At this there is no such type as ???link??™ in PHP and so it??™s impossible to check what $ref2 is.

Generally basing on the work of the template we may say that PHP differentiates links types.

Now I??™ll try to formulate more precisely what exactly embarrasses me.

<?php 
class Simple 
{ 
    public $name; 
} 

$obj1 = new Simple(); 
$obj1->name = 'obj1'; 

$obj2 = new Simple(); 
$obj2->name = 'obj2'; 

$ref1 = $obj1; 

$ref1 = $obj2; 

print 'name: '.$obj1->name; // "name: obj1" 
?>

As it is known objects in PHP5 are transmitted via link i.e. string $ref1 = $obj1 is equal to $ref1 =& $obj1. We??™ll try to replace this string:

<?php 
$ref1 =& $obj1; 

$ref1 = $obj2; 

print 'name: '.$obj1->name; // in this case "name: obj2" 
?>

Strings $ref1 = $obj1 and $ref1 =& $obj1 turn out not to be equal.

We??™ll try to change the following string:

<?php 
$ref1 =& $obj1; 

$ref1 =& $obj2; 

print 'name: '.$obj1->name; // in this case "name: obj1" 
?>

It is quite logical because it has to be so.

Generally speaking in case with objects links act according to some other rules which are not described in the manual or maybe I have missed something??¦

OK, I??™ve found. It has been already discussed here http://www.php.net/manual/en/language.oop5.basic.php

In the unit ???new??™

<?php 
$assigned  =  $instance; 
$reference =& $instance; 

$instance->var = '$assigned will have this value'; 

$instance = null; // $instance and $reference become null 

var_dump($instance); 
var_dump($reference); 
var_dump($assigned); 
?>

The above example will output:

NULL 
NULL 
object(SimpleClass)#1 (1) { 
   ["var"]=> 
     string(30) "$assigned will have this value" 
}

Also
http://www.php.net/manual/en/language.o … .php#50469
http://www.php.net/manual/en/language.o … .php#64410
In the unit "User Contributed Notes"