This function returns TRUE if the object
object, belongs to a class which is a
subclass of class_name, FALSE otherwise.
Note:
Since PHP 5.0.3 you may also specify the object
parameter as a string (the name of the class).
Example 1. is_subclass_of() example
<?php // define a class class WidgetFactory { var $oink = 'moo'; }
// define a child class class WidgetFactory_Child extends WidgetFactory { var $oink = 'oink'; }
// create a new object $WF = new WidgetFactory(); $WFC = new WidgetFactory_Child();
if (is_subclass_of($WFC, 'WidgetFactory')) { echo "yes, \$WFC is a subclass of WidgetFactory\n"; } else { echo "no, \$WFC is not a subclass of WidgetFactory\n"; }
if (is_subclass_of($WF, 'WidgetFactory')) { echo "yes, \$WF is a subclass of WidgetFactory\n"; } else { echo "no, \$WF is not a subclass of WidgetFactory\n"; }
// usable only since PHP 5.0.3 if (is_subclass_of('WidgetFactory_Child', 'WidgetFactory')) { echo "yes, WidgetFactory_Child is a subclass of WidgetFactory\n"; } else { echo "no, WidgetFactory_Child is not a subclass of WidgetFactory\n"; } ?>
The above example will output:
yes, $WFC is a subclass of WidgetFactory
no, $WF is not a subclass of WidgetFactory
yes, WidgetFactory_Child is a subclass of WidgetFactory