# is_subclass_of

(PHP 4, PHP 5)

is_subclass_of — Checks if the object has this class as one of its parents

### Description

bool is_subclass_of ( mixed `$object` , string `$class_name` )

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

### See Also

- get_class()
- get_parent_class()
- is_a()