3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $arr = array('key' => 'value'); //array_map(function($k, $v){var_dump($k, $v);}, array_keys($arr), $arr); array_map(function(&$a){ var_dump(key($a)); }, $arr);
based on 43tWK
Output for 5.3.0 - 5.6.28, 7.0.0 - 7.1.0
Warning: key() expects parameter 1 to be array, string given in /in/P2ul8 on line 7 NULL
Output for hhvm-3.10.0 - 3.12.0
Warning: Invalid operand type was used: expecting an array in /in/P2ul8 on line 7 bool(false)
Output for 4.4.2 - 4.4.9, 5.1.0 - 5.2.17
Parse error: syntax error, unexpected T_FUNCTION, expecting ')' in /in/P2ul8 on line 5
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 T_FUNCTION, expecting ')' in /in/P2ul8 on line 5
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error, expecting `')'' in /in/P2ul8 on line 5
Process exited with code 255.