note 56820 deleted from language.references.pass by googleguy
| From: | googleguy@php.net | Date: | Sun, 23 Feb 2014 17:13:56 +0000 |
| Subject: | note 56820 deleted from language.references.pass by googleguy | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-198602@lists.php.net to get a copy of this message | ||
Note Submitter: rmarscher
----
Not sure if this is obvious to everyone, but if you pass an object by reference into a function and
then set that variable to the reference of a new object, the initial variable outside the function
is still pointing to the original object.
It became obvious to me why this is the case when I made a little diagram of what's actually
happening in the system's memory, but before that when I was just looking at the code, it took
me a while of testing before I realized what was going on.
Here's an example (I haven't tried in PHP5, but I would guess it works the same):
<?php
class Foo {}
class Bar {}
function & createBar()
{
return new Bar;
}
function setBar(& $obj)
{
echo get_class($obj) . "\n";
$obj = & createBar();
echo get_class($obj) . "\n";
}
$test = new Foo;
setBar($test);
echo get_class($test);
?>
Outputs:
foo
bar
foo