(PHP 4, PHP 5, PHP 7)
is_subclass_of — ����˶����Ǹ�������࣬�� TRUE
$object
, string $class_name
) : bool
������� object
���������� class_name
�����࣬�� TRUE������ FALSE��
Note:
�� PHP 5.0.3 ��Ҳ������һ���ַ�����ָ��
object��������������
Example #1 is_subclass_of() ����
<?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";
}
?>
�������̻������
yes, $WFC is a subclass of WidgetFactory no, $WF is not a subclass of WidgetFactory yes, WidgetFactory_Child is a subclass of WidgetFactory
�μ� get_class()�� get_parent_class() �� is_a()��
objectA class name or an object instance
class_nameThe class name
allow_string
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.
| �汾 | ˵�� |
|---|---|
| 5.3.9 |
Added allow_string parameter
|
| 5.0.3 |
You may also specify the object parameter as a
string (the name of the class)
|
Example #2 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";
}
?>
�������̻������
yes, $WFC is a subclass of WidgetFactory no, $WF is not a subclass of WidgetFactory yes, WidgetFactory_Child is a subclass of WidgetFactory
Note:
����������֪�࣬ʹ�ô˺�����ʹ���κ���ע��� autoloader��