3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = &$b; $b = 1; echo $a; echo "\n---\n"; $c = &$d[0]; $d = [1]; var_dump($c);
Output for 7.1.25 - 7.1.33, 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 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.12
1 --- NULL
preferences:
128.56 ms | 407 KiB | 5 Q