php interface method overriding

Question

<?php
interface a {
    public function bar();
}
interface b extends a {
    public function foo();
    public function bar($a);
}

?>

It is showing a fatal error of signature missmatch in method. is not it possible to override a method of interface in php?

Answer 1

You're getting the signature mismatch error because the two bar functions aren't compatible.

You can fix it by changing the interface to

interface b extends a {
    public function foo();
    public function bar($a = null);
}

Although this might not be a complete solution, as you will now get a Can't inherit abstract function error.