PHP 5 >= 5.1.0, PHP 7, PHP 8
spl_autoload_register - Register given function as __autoload() implementation
Code Examples

     [callable|null$callback = null],
     [bool$throw = true],
     [bool$prepend = false]
): bool

Register a function with the spl provided __autoload queue. If the queue is not yet activated it will be activated.

If your code has an existing __autoload function then this function must be explicitly registered on the __autoload queue. This is because spl_autoload_register will effectively replace the engine cache for the __autoload function by either spl_autoload or spl_autoload_call.

If there must be multiple autoload functions, spl_autoload_register allows for this. It effectively creates a queue of autoload functions, and runs through each of them in the order they are defined. By contrast, __autoload may only be defined once.



The autoload function being registered. If null, then the default implementation of spl_autoload will be registered.

callback( string$class_name ): void

This parameter specifies whether spl_autoload_register should throw exceptions when the callback cannot be registered.


If true, spl_autoload_register will prepend the autoloader on the autoload queue instead of appending it.

Return Values

Returns true on success or false on failure.


Version Description
8.0.0 callback is now nullable.

Related Functions

Example of spl_autoload_register

Show all examples for spl_autoload_register

PHP Version:

Function spl_autoload_register:

Standard PHP Library (SPL) Functions

Most used PHP functions