PHP Check if Variable is an Instance of “Any” Classes

<?php function is_instance($x) { // not an object, not an instance if (!is_object($x)) return false; return ($x = get_class($x)) && $x !== 'stdClass'; } // check if `$foo` is an instance of `Foo` class $foo = new Foo; if ($foo instanceof Foo) { echo 'true'; } // check if `$foo` is an instance of any class $foo = new Bar; if (is_instance($foo)) { echo 'true'; }