b cannot implement a - it is not an interface

Description

implements is a keyword that only applies to interfaces. Classes, traits and enum are all triggering this message.

The error message also applies with the extends keyword, when building an inteface.

Example

<?php

class a {}

class b implements a {}

interface b extends a {}

?>

Solutions

• Use an interface instead of a class.

• Convert the class to an interface, then implements this interface.

• Change the implemented or extended class to an actual interface.