引用的解释

时间：2011-05-16 15:55:22 来源：站内作者：潘春会

++;
echo "increment $a->ref->id++; ";

print_r($a);
echo " ";
print_r($b);
echo " ";
echo "$a2=unserialize(serialize($a)); ";
$a2=unserialize(serialize($a));

print_r($a2);
echo " ";
print_r($b);
echo " ";

$a2->ref->id++;
echo "increment $a2->ref->id++; ";

print_r($a2);
echo " ";
print_r($b);
echo " ";
?>

Output on PHP 5.3.3:
foo Object ( [ref] => foo Object ( [ref] => [id] => 1 ) [id] => 0 )
foo Object ( [ref] => [id] => 1 )

increment $a->ref->id++;

foo Object ( [ref] => foo Object ( [ref] => [id] => 2 ) [id] => 0 )
foo Object ( [ref] => [id] => 2 )

$a2=unserialize(serialize($a));

foo Object ( [ref] => foo Object ( [ref] => [id] => 2 ) [id] => 0 )
foo Object ( [ref] => [id] => 2 )

increment $a2->ref->id++;

foo Object ( [ref] => foo Object ( [ref] => [id] => 3 ) [id] => 0 )
foo Object ( [ref] => [id] => 2 )

after unserialize $a2->ref isn't any more a reference.

To save items for the next request, you must avoid references and save all objects of a class in an array. To get a PHP-reference you could write a function like:
<?php
function get_obj_by_ref($ref){
 global $_array_where_objects_of_class_foo_are_stored;
 $r = &$_array_where_objects_of_class_foo_are_stored[$ref];
 return $r;
}
?>

I am unhappy about this behavior of PHP. I does not watch like a feature ... ;)

gnuffo1 at gmail dot com (28-Aug-2010 10:07)

If you want to know the reference count of a particular variable, then here's a function that makes use of debug_zval_dump() to do so:



<?php

function refcount($var
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