%s %s cannot implement previously implemented interface %s¶
Description¶
This error reports that an interface has already been implemented by a parent, and, as such, should not be implemented again.
For enumerations, it applies to BackEnum
and UnitEnum
, as enumerations don’t have parents.
For interfaces and classes, it applies to repetitions of interfaces in the implements list.
It doesn’t apply to duplicate implements between a parent and a child class or interface.
It doesn’t apply to trait, that have no relationship with interfaces.
Example¶
<?php
enum X implements UnitEnum {}
interface J extends I, I {}
class X implements I {}
// This is OK
// It is also duplicate and useless, but valid.
class Y extends X implements I {}
?>
Literal Examples¶
Enum x cannot implement previously implemented interface UnitEnum
Solutions¶
Remove duplicate interfaces from the
implements
keyword on classes.Remove duplicate interfaces from the
extends
keyword on interfaces.Remove
BackEnum
andUnitEnum
from theimplements
keyword on an enumeration.