--TEST-- Checking if exists interface, trait, abstract and final class --FILE-- <?php interface a { } abstract class b { } final class c { } trait d {} var_dump(class_exists('a')); var_dump(class_exists('b')); var_dump(class_exists('c')); var_dump(class_exists('d')); ?> --EXPECT-- bool(false) bool(true) bool(true) bool(false)