3v4l.org

run code in 300+ PHP versions simultaneously
<?php class x { public function m() {} } class y extends x { public function m():?string {} } $x = new x(); $y = new y(); $x->m(); $y->m();
Output for 8.0.1 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Fatal error: Uncaught TypeError: y::m(): Return value must be of type ?string, none returned in /in/Y1UXW:8 Stack trace: #0 /in/Y1UXW(14): y->m() #1 {main} thrown in /in/Y1UXW on line 8
Process exited with code 255.
preferences:
110.11 ms | 402 KiB | 89 Q