3v4l.org

run code in 300+ PHP versions simultaneously
<?php interface A {} interface B extends A {} interface X { public function foo(B $a); } interface Y extends X { public function foo(A $a); }
Output for 7.4.0 - 7.4.27, 8.0.0 - 8.0.15, 8.1.0 - 8.1.2
Output for 7.1.0 - 7.1.24, 7.2.0 - 7.2.33, 7.3.16 - 7.3.33
Fatal error: Declaration of Y::foo(A $a) must be compatible with X::foo(B $a) in /in/7LCLB on line 10
Process exited with code 255.
Output for 5.6.38
Fatal error: Declaration of Y::foo() must be compatible with X::foo(B $a) in /in/7LCLB on line 10
Process exited with code 255.

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