PHP class_exists Check if class is defined

PHP class_exists Check if the class is defined Class_exists

(PHP 4, PHP 5)

class_exists- Checking whether a class is defined

Description

bool class_exists ( string $class _name [, bool $autoload ])

If the class referred to by class_name is already defined, this function returns TRUE, otherwise FALSEis returned.

Example #1 class_exists () Example

< Span class= "type" > <?php
// check the class exists before  Trying to use it
if  (class_ Exists ( MyClass '      $myclass  =  new myclass ();
}

?>

class_exists () will attempt to call __autoload by default, and if you do not want class_exists () to call __autoload, you can AutoLoad The parameter is set to FALSE.

Example #2 autoload parameter examples

<?php
function__autoload($class)
{
Include$class.'. php ');

Check to see if 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 ();
}

?>

Note:

The autoload parameter is added to PHP 5.

See interface_exists () and get_declared_classes ().

PHP class_exists Check if class is defined