Delicious Bookmark this on Delicious Share on Facebook SlashdotSlashdot It! Digg! Digg



PHP : Function Reference : Class/Object Functions : is_subclass_of

is_subclass_of

Checks if the object has this class as one of its parents (PHP 4, PHP 5)
bool is_subclass_of ( mixed object, string class_name )

Example 385. 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

Related Examples ( Source code ) » is_subclass_of


Code Examples / Notes » is_subclass_of

01-oct-2005 02:32

this function does not check interfaces, unlike instanceof operator.

gunniboyh

is_subclass_of() works also with classes between the class of obj and the superclass.
example:
<?php
class A {};
class B extends A {};
class C extends B {};
$foo=new C();
echo ((is_subclass_of($foo,'A')) ? 'true' : 'false');
?>
echoes 'true' .


ondra zizka

For PHP4:
/** Returns whether specified class is subclass of the other class. */
function is_subclass($sClass, $sExpectedParentClass){
do if( $sExpectedParentClass === $sClass ) return true;
while( false != ($sClass = get_parent_class($sClass)) );
return false;
}
// Test:
class A {} class B extends A {} class C extends B {} echo (int) is_subclass('C', 'A');


youcantryreachingme

A bug report at http://pear.php.net/bugs/bug.php?id=2975 indicates that the "is_subclass_of" function can return the error message:
Warning: Unknown class passed as parameter
in the event that the class represented by the second argument hasn't yet been instantiated.


Change Language


Follow Navioo On Twitter
call_user_method_array
call_user_method
class_exists
get_class_methods
get_class_vars
get_class
get_declared_classes
get_declared_interfaces
get_object_vars
get_parent_class
interface_exists
is_a
is_subclass_of
method_exists
property_exists
eXTReMe Tracker