3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = [ 'net_sec1' => 'a', 'net_sec2' => 'b', 'net_sec3' => 'c', 'ss_ks_kw' => 'd', ]; $aa = preg_grep( '/^net_sec(\d+)$/', array_flip($a) ); var_dump($aa);
based on H0KSm
Output for 5.4.0 - 7.2.0
array(3) { ["a"]=> string(8) "net_sec1" ["b"]=> string(8) "net_sec2" ["c"]=> string(8) "net_sec3" }
Output for 4.4.2 - 4.4.9, 5.1.0 - 5.3.29
Parse error: syntax error, unexpected '[' in /in/j6Hmp on line 3
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/j6Hmp on line 3
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error in /in/j6Hmp on line 3
Process exited with code 255.