3v4l.org

run code in 300+ PHP versions simultaneously
<?php echo serialize(1), PHP_EOL; echo serialize('s'), PHP_EOL; echo serialize(null), PHP_EOL; echo serialize(false), PHP_EOL; echo serialize([]), PHP_EOL; echo serialize([1]), PHP_EOL; echo serialize([1, 2]), PHP_EOL; echo serialize([1, "x" => [-1]]), PHP_EOL;
Output for 8.1.0 - 8.1.28, 8.2.0 - 8.2.19, 8.3.0 - 8.3.7
i:1; s:1:"s"; N; b:0; a:0:{} a:1:{i:0;i:1;} a:2:{i:0;i:1;i:1;i:2;} a:2:{i:0;i:1;s:1:"x";a:1:{i:0;i:-1;}}
preferences:
43.71 ms | 402 KiB | 62 Q