is_a(3) [php man page]

IS_A(3) 								 1								   IS_A(3)

is_a - Checks if the object is of this class or has this class as one of its parents

SYNOPSIS

       bool is_a FALSE (object	$object, string  $class_name, [bool  $allow_string])

DESCRIPTION

	Checks if the given $object is of this class or has this class as one of its parents.

PARAMETERS

	      o $object
		- The tested object

	      o $class_name
		- The class name

	      o $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.

RETURN VALUES

	Returns TRUE if the object is of this class or has this class as one of its parents, FALSE otherwise.

CHANGELOG

       +--------+---------------------------------------------------+
       |Version |						    |
       |	|						    |
       |	|		     Description		    |
       |	|						    |
       +--------+---------------------------------------------------+
       | 5.3.9	|						    |
       |	|						    |
       |	|	    Added $allow_string parameter	    |
       |	|						    |
       | 5.3.0	|						    |
       |	|						    |
       |	|  This function is no longer deprecated, and  will |
       |	| therefore no longer throw E_STRICT warnings.	    |
       |	|						    |
       | 5.0.0	|						    |
       |	|						    |
       |	|  This function became deprecated in favour of the |
       |	| instanceof operator. Calling this  function  will |
       |	| result in an E_STRICT warning.		    |
       |	|						    |
       +--------+---------------------------------------------------+
EXAMPLES

       Example #1

	      is_a(3) example

	      <?php
	      // define a class
	      class WidgetFactory
	      {
		var $oink = 'moo';
	      }

	      // create a new object
	      $WF = new WidgetFactory();

	      if (is_a($WF, 'WidgetFactory')) {
		echo "yes, $WF is still a WidgetFactory
";
	      }
	      ?>

       Example #2

	      Using the instanceof operator in PHP 5

	      <?php
	      if ($WF instanceof WidgetFactory) {
		  echo 'Yes, $WF is a WidgetFactory';
	      }
	      ?>

SEE ALSO

       get_class(3), get_parent_class(3), is_subclass_of(3).

PHP Documentation Group 														   IS_A(3)

IS_SUBCLASS_OF(3)							 1							 IS_SUBCLASS_OF(3)

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

SYNOPSIS

       bool is_subclass_of TRUE (mixed	$object, string  $class_name, [bool  $allow_string])

DESCRIPTION

	Checks if the given $object has the class $class_name as one of its parents.

PARAMETERS

	      o $object
		- A class name or an object instance. No error is generated if the class does not exist.

	      o $class_name
		- The class name

	      o $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.

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		    |
       |	|						    |
       +--------+---------------------------------------------------+
       | 5.3.9	|						    |
       |	|						    |
       |	|	    Added $allow_string parameter	    |
       |	|						    |
       | 5.3.7	|						    |
       |	|						    |
       |	|  Added  support  for	$class_name  to  work  with |
       |	| interfaces					    |
       |	|						    |
       | 5.0.3	|						    |
       |	|						    |
       |	|  You	may also specify the $object parameter as a |
       |	| string (the name of the class)		    |
       |	|						    |
       +--------+---------------------------------------------------+
EXAMPLES

       Example #1

	      is_subclass_of(3) 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
";
	      } else {
		echo "no, $WFC is not a subclass of WidgetFactory
";
	      }

	      if (is_subclass_of($WF, 'WidgetFactory')) {
		echo "yes, $WF is a subclass of WidgetFactory
";
	      } else {
		echo "no, $WF is not a subclass of WidgetFactory
";
	      }

	      // usable only since PHP 5.0.3
	      if (is_subclass_of('WidgetFactory_Child', 'WidgetFactory')) {
		echo "yes, WidgetFactory_Child is a subclass of WidgetFactory
";
	      } else {
		echo "no, WidgetFactory_Child is not a subclass of WidgetFactory
";
	      }
	      ?>

	      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

       Example #2

	      is_subclass_of(3) using interface example

	      <?php
	      // Define the Interface
	      interface MyInterface
	      {
		public function MyFunction();
	      }

	      // Define the class implementation of the interface
	      class MyClass implements MyInterface
	      {
		public function MyFunction()
		{
		  return "MyClass Implements MyInterface!";
		}
	      }

	      // Instantiate the object
	      $my_object = new MyClass;

	      // Works since 5.3.7

	      // Test using the object instance of the class
	      if (is_subclass_of($my_object, 'MyInterface')) {
		echo "Yes, $my_object is a subclass of MyInterface
";
	      } else {
		echo "No, $my_object is not a subclass of MyInterface
";
	      }

	      // Test using a string of the class name
	      if (is_subclass_of('MyClass', 'MyInterface')) {
		echo "Yes, MyClass is a subclass of MyInterface
";
	      } else {
		echo "No, MyClass is not a subclass of MyInterface
";
	      }
	      ?>

	      The above example will output:

	      Yes, $my_object is a subclass of MyInterface
	      Yes, MyClass is a subclass of MyInterface

NOTES

       Note

	      Using this function will use any registered autoloaders if the class is not already known.

SEE ALSO

       get_class(3), get_parent_class(3), is_a(3), class_parents(3).

PHP Documentation Group 													 IS_SUBCLASS_OF(3)