3v4l.org

run code in 300+ PHP versions simultaneously
<?php interface Foo extends Psr { function f($x); } interface Psr { function f(string $x); } class Clazz implements Foo { function f(string $x) {} }
Output for 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.30, 8.2.0 - 8.2.25, 8.3.0 - 8.3.13
Fatal error: Declaration of Clazz::f(string $x) must be compatible with Foo::f($x) in /in/n8U4f on line 15
Process exited with code 255.
Output for 7.3.0 - 7.3.33
Fatal error: Declaration of Clazz::f(string $x) must be compatible with Foo::f($x) in /in/n8U4f on line 13
Process exited with code 255.
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