Question

On PHP.net the description for __autoload reads “Attempt to load undefined class”. However, it states you can define the function “to enable classes autoloading.” So, say I define the function like this:

function __autoload($className) {
    if (file_exists(ROOTDIRECTORY . $className . '.class.php')) {
        require_once(ROOTDIRECTORY . $className . '.class.php');
    }
}

Will __autoload still only load classes that haven’t been defined yet, or will the guts of the function as they are written above override this feature?

Answer 1

Yes, it will only trigger for classes that have yet to be included. This means you can replace require_once() with a simpler require() which reduces the amount of overhead processing PHP has to do in the background.

Also, you should add an else { return false; } to your function so that PHP triggers the appropriate error if it cannot locate the class file.