3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = array(1=>"test",2=>"test2"); $array[1]=&$array; $array[2]=&$array[1]; print_r($array);
Output for 7.0.0 - 7.0.33, 7.1.0 - 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 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.4, 8.3.6
Array ( [1] => Array *RECURSION* [2] => Array *RECURSION* )
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 Array ( [1] => Array *RECURSION* [2] => Array *RECURSION* )
Output for 5.6.0 - 5.6.40
Array ( [1] => Array ( [1] => Array *RECURSION* [2] => Array *RECURSION* ) [2] => Array ( [1] => Array *RECURSION* [2] => Array *RECURSION* ) )
preferences:
243.2 ms | 402 KiB | 291 Q