Comparing Objects
When using the comparison operator (==),
object variables are compared in a simple manner, namely: Two object
instances are equal if they have the same attributes and values, and are
instances of the same class.
When using the identity operator (===),
object variables are identical if and only if they refer to the same
instance of the same class.
An example will clarify these rules.
Example of object comparison in PHP 5
flag = $flag;
}
}
class OtherFlag
{
public $flag;
function OtherFlag($flag = true) {
$this->flag = $flag;
}
}
$o = new Flag();
$p = new Flag();
$q = $o;
$r = new OtherFlag();
echo "Two instances of the same class\n";
compareObjects($o, $p);
echo "\nTwo references to the same instance\n";
compareObjects($o, $q);
echo "\nInstances of two different classes\n";
compareObjects($o, $r);
?>
]]>
&example.outputs;
Extensions can define own rules for their objects comparison
(==).