3v4l.org

run code in 300+ PHP versions simultaneously
<?php class A { public function __invoke() { return "hello"; } } $a = new A; var_dump(is_callable($a)); function my_echo(callable $a) { echo $a() . PHP_EOL; var_dump($a instanceof A); } my_echo($a);

preferences:
111.96 ms | 1940 KiB | 5 Q