class_exists(3) [php man page]

CLASS_EXISTS(3) 							 1							   CLASS_EXISTS(3)

class_exists - Checks if the class has been defined

SYNOPSIS

       bool class_exists (string  $class_name, [bool  $autoload = true])

DESCRIPTION

	This function checks whether or not the given class has been defined.

PARAMETERS

	      o $class_name
		- The class name. The name is matched in a case-insensitive manner.

	      o $autoload
		- Whether or not to call __autoload by default.

RETURN VALUES

	Returns TRUE if $class_name is a defined class, FALSE otherwise.

CHANGELOG

       +--------+---------------------------------------------------+
       |Version |						    |
       |	|						    |
       |	|		     Description		    |
       |	|						    |
       +--------+---------------------------------------------------+
       | 5.0.2	|						    |
       |	|						    |
       |	|  No  longer  returns TRUE for defined interfaces. |
       |	| Use interface_exists(3).			    |
       |	|						    |
       +--------+---------------------------------------------------+
EXAMPLES

       Example #1

	      class_exists(3) example

	      <?php
	      // Check that the class exists before trying to use it
	      if (class_exists('MyClass')) {
		  $myclass = new MyClass();
	      }

	      ?>

       Example #2

	      $autoload parameter example

	      <?php
	      function __autoload($class)
	      {
		  include($class . '.php');

		  // Check to see whether the include declared the class
		  if (!class_exists($class, false)) {
		      trigger_error("Unable to load class: $class", E_USER_WARNING);
		  }
	      }

	      if (class_exists('MyClass')) {
		  $myclass = new MyClass();
	      }

	      ?>

SEE ALSO

       function_exists(3), interface_exists(3), get_declared_classes(3).

PHP Documentation Group 													   CLASS_EXISTS(3)

CLASS_IMPLEMENTS(3)							 1						       CLASS_IMPLEMENTS(3)

class_implements - Return the interfaces which are implemented by the given class or interface

SYNOPSIS

       array class_implements (mixed  $class, [bool  $autoload = true])

DESCRIPTION

	This function returns an array with the names of the interfaces that the given $class and its parents implement.

PARAMETERS

	      o $class
		- An object (class instance) or a string (class or interface name).

	      o $autoload
		- Whether to allow this function to load the class automatically through the __autoload(3) magic method.

RETURN VALUES

	An array on success, or FALSE on error.

CHANGELOG

       +--------+---------------------------------------------------+
       |Version |						    |
       |	|						    |
       |	|		     Description		    |
       |	|						    |
       +--------+---------------------------------------------------+
       | 5.1.0	|						    |
       |	|						    |
       |	|  Added the option to pass the $class parameter as |
       |	| a string. Added the $autoload parameter.	    |
       |	|						    |
       +--------+---------------------------------------------------+
EXAMPLES

       Example #1

	      class_implements(3) example

	      <?php

	      interface foo { }
	      class bar implements foo {}

	      print_r(class_implements(new bar));

	      // since PHP 5.1.0 you may also specify the parameter as a string
	      print_r(class_implements('bar'));

	      function __autoload($class_name) {
		 require_once $class_name . '.php';
	      }

	      // use __autoload to load the 'not_loaded' class
	      print_r(class_implements('not_loaded', true));

	      ?>

	      The above example will output something similar to:

	      Array
	      (
		  [foo] => foo
	      )

	      Array
	      (
		  [interface_of_not_loaded] => interface_of_not_loaded
	      )

SEE ALSO

       class_parents(3), get_declared_interfaces(3).

PHP Documentation Group 												       CLASS_IMPLEMENTS(3)