3v4l.org

run code in 500+ PHP versions simultaneously
<?php interface Foo { public function bar(): Foo; } class A implements Foo { public function bar(): self { } }
Output for 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.31, 8.3.0 - 8.3.31, 8.4.1 - 8.4.22, 8.5.0 - 8.5.7
Output for 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33
Fatal error: Declaration of A::bar(): A must be compatible with Foo::bar(): Foo in /in/R78b3 on line 7
Process exited with code 255.

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