3v4l.org

run code in 300+ PHP versions simultaneously
<?php class A { public function __construct(int $x) { echo $x; } } class B extends A { public function __construct(int $y) { parent::__construct($y); } } new B(123);
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
123

preferences:
117.07 ms | 1474 KiB | 4 Q