What is the method to detect whether a class exists in PHP?

getMessage(); } /** * The above code either includes myfile.php or throws the new MyException * as expected. No problem right? The same should be true of class_exists(), * right? So then... */ $classname = 'NonExistentClass'; try { if( ! class_exists( $classname ) ) { throw new MyException('Double Doh!'); } $var = new $classname(); } catch( MyException $e ) { echo $e->getMessage(); } /** * Should throw a new instance of MyException. But instead I get an * uncaught LogicException blah blah blah for the default Exception * class AND MyException. I only catch MyException so we've got on * uncaught resulting in the dreaded LogicException error. */ ?>