3v4l.org

run code in 300+ PHP versions simultaneously
<?php $calc = function ($arg = null, $acc = '') use (&$calc) { return $arg === null ? $acc : function ($arg = null, $acc = '') use (&$calc) { return $calc($arg, $acc . $arg); }; }; $result = $calc(1)(3)(3)(8)(); var_dump($result);
Output for 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.0 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.4, 8.3.6
string(0) ""
Output for 8.3.5
Warning: PHP Startup: Unable to load dynamic library 'sodium.so' (tried: /usr/lib/php/8.3.5/modules/sodium.so (libsodium.so.23: cannot open shared object file: No such file or directory), /usr/lib/php/8.3.5/modules/sodium.so.so (/usr/lib/php/8.3.5/modules/sodium.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0 string(0) ""

preferences:
134.45 ms | 402 KiB | 173 Q