Checks if the given object
has the class class_name
as one of its parents or implements it.
A class name or an object instance. No error is generated if the class does not exist.
The class name
If this parameter set to false, string class name as object
is not allowed. This also prevents from calling autoloader if the class doesn't exist.
This function returns TRUE
if the object object
, belongs to a class which is a subclass of class_name
, FALSE
otherwise.
Added allow_string
parameter
Added support for class_name
to work with interfaces
You may also specify the object
parameter as a string (the name of the class)
Using this function will use any registered autoloaders if the class is not already known.
<?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
<?php // Define the Interface interface MyInterface { public function MyFunction(); } // Define the class implementation of the interface class MyClass implements MyInterface { public function MyFunction() { return "MyClass Implements MyInterface!"; } } // Instantiate the object $my_object = new MyClass; // Works since 5.3.7 // Test using the object instance of the class if (is_subclass_of($my_object, 'MyInterface')) { echo "Yes, \$my_object is a subclass of MyInterface\n"; } else { echo "No, \$my_object is not a subclass of MyInterface\n"; } // Test using a string of the class name if (is_subclass_of('MyClass', 'MyInterface')) { echo "Yes, MyClass is a subclass of MyInterface\n"; } else { echo "No, MyClass is not a subclass of MyInterface\n"; } ?>
The above example will output:
Yes, $my_object is a subclass of MyInterface Yes, MyClass is a subclass of MyInterface
is_a() -
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