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?

It's possible if it has the same signature. Your b.bar accepts $a, while a.bar does not, which is the source of the fatal error. — Yoshi
– Yoshi, Commented Jul 19, 2012 at 14:07
@Yoshi what is the point if it has the same signature. What is the point altogether. — Esailija
– Esailija, Commented Jul 19, 2012 at 14:07
@Esailija That's a thing you'll have to ask the php devs. I just pointed out the error, that tripped me often enough myself ;) — Yoshi
– Yoshi, Commented Jul 19, 2012 at 14:08
@Esailija You are still able to implement the same function in another way. You may also emulate overloading using func_get_args() — feeela
– feeela, Commented Jul 19, 2012 at 14:13
@yoshi i know the reason of the error. i want to know if it is possible or not in this way or any other way to do it. — varuog
– varuog, Commented Jul 19, 2012 at 14:18

Jrgns · Accepted Answer · 2012-09-04 15:54:25Z

3

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.

answered Sep 4, 2012 at 15:54

Jrgns

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1 Comment

The Can't inherit... error is a php bug, fixed in 5.3.9.