class.extendsInterface

Code example

<?php declare(strict_types = 1);

interface BazInterface
{
}

class Foo extends BazInterface
{
}

Why is it reported?

A class is attempting to extend an interface using the extends keyword. In PHP, classes cannot extend interfaces. Interfaces must be implemented using the implements keyword instead. The extends keyword is only valid for extending another class.

This is a compile-level error in PHP and will cause a fatal error at runtime.

How to fix it

Use implements instead of extends when a class needs to use an interface:

 <?php declare(strict_types = 1);

 interface BazInterface
 {
 }

-class Foo extends BazInterface
+class Foo implements BazInterface
 {
 }