3v4l.org

run code in 300+ PHP versions simultaneously
<?php class Super{} class Child extends Super{} abstract class A{ abstract function xxx(): Super; } abstract class B extends A{ /** @return Child */ abstract function xxx(): Super; }
Output for 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
Output for 7.0.0 - 7.0.33, 7.1.0 - 7.1.33
Fatal error: Can't inherit abstract function A::xxx() (previously declared abstract in B) in /in/IOJbu on line 13
Process exited with code 255.
Output for 5.6.38 - 5.6.40
Parse error: syntax error, unexpected ':', expecting ';' or '{' in /in/IOJbu on line 7
Process exited with code 255.
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98.31 ms | 1760 KiB | 4 Q