- var_dump: documentation ( source)
<?php
$a = new stdClass;
$b = &$a;
var_dump(is_ref($a, $b));
function is_ref(&$a, &$b)
{
if ($a !== $b)
return false;
// create a unique different value
$differentValue = ($a === true) ? false : true;
// We need a copy of $a, to keep safe. Note that if $a is a "referenced" value, $copy will be too.
$copy = $a;
// Change $a and check if $b changed too, finally restore $a using $copy.
$a = $differentValue;
$same = $a === $b;
$a = $copy;
return $same;
}