Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Variables Configuration Options
Name Default Changeable Changelog
unserialize_callback_func null PHP_INI_ALL  
For further details and definitions of the PHP_INI_* modes, see the Where a configuration setting may be set.

Here's a short explanation of the configuration directives.

unserialize_callback_func string

The callback specified is called when unserialize() attempts to use an undefined class. A warning appears if the specified callback function is not defined, or if the callback function fails to define the missing class.

See also unserialize() and Autoloading Objects.