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# is_subclass_of

(PHP 4, PHP 5)

is_subclass_of -- Returns `TRUE` if the object has this class as one of its parents

## Description

bool is_subclass_of ( mixed object, string class_name )

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

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

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