PHP : Function Reference : Class/Object Functions : is_subclass

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:

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yes, $WFC is a subclass of WidgetFactory

no, $WF is not a subclass of WidgetFactory

yes, WidgetFactory_Child is a subclass of WidgetFactory

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.

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

Related Examples ( Source code ) » is_subclass_of

Code Examples / Notes » is_subclass_of

Change Language

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

Related Examples ( Source code ) » is_subclass_of

Code Examples / Notes » is_subclass_of

Change Language

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 )