is_subclass_of
(PHP 4, PHP 5)
is_subclass_of — Checks if the object has this class as one of its parents
Description
Checks if the given object has the class class_name as one of its parents.
Parameters
- object
-
A class name or an object instance
- class_name
-
The class name
Return Values
This function returns TRUE if the object object, belongs to a class which is a subclass of class_name, FALSE otherwise.
Changelog
| Version | Description |
|---|---|
| 5.0.3 | You may also specify the object parameter as a string (the name of the class) |
Examples
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
Notes
Note:
Using this function will use any registered autoloaders if the class is not already known.
See Also
- get_class() - Returns the name of the class of an object
- get_parent_class() - Retrieves the parent class name for object or class
- is_a() - Checks if the object is of this class or has this class as one of its parents