is_subclass_of

Description

This function returns TRUE if the object object, belongs to a class which is a subclass of class_name, FALSE otherwise.

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

See also get_class(), get_parent_class() and is_a().