3v4l.org

run code in 300+ PHP versions simultaneously
<?php var_export( array_merge( ['x' => 'X', 5 => 'five'], ['y' => 'Y', 5 => 'FIVE']));
Output for 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 - 8.3.4, 8.3.6 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
array ( 'x' => 'X', 0 => 'five', 'y' => 'Y', 1 => 'FIVE', )
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 ( 'x' => 'X', 0 => 'five', 'y' => 'Y', 1 => 'FIVE', )

preferences:
100.99 ms | 1253 KiB | 4 Q