3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $arr = array ( 0 => 'nested array', 1 => 'nested array', 2 => 'nested array', 3 => 'nested array', 4 => 'nested array', 5 => 'nested array', ); var_dump(key(array_diff(array_keys(array_values($arr)), array_keys($arr))))?:NULL;
Output for 5.3.0 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
NULL
Output for 4.4.2 - 4.4.9, 5.1.0 - 5.2.17
Parse error: syntax error, unexpected ':' in /in/1eVn9 on line 12
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.4.1, 5.0.0 - 5.0.5
Parse error: parse error, unexpected ':' in /in/1eVn9 on line 12
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error in /in/1eVn9 on line 12
Process exited with code 255.