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)
