Online PHP editor | refs for XBYKc

<?php $array = Array ( "field_5abcb693a68bc" => Array ( "0" => Array ( "field_5abcbb1b51ddf" => "mortgage", "field_5ae58a0b58b58" => "", "field_5abcbb1e51de0" => "10", "field_5abcbb2351de2" => "45,654,456", "field_5abcbb6251de3" => "", "field_5abcbb6651de4" => "04/2017", "field_5abcbb6851de5" => "4,454,656", "field_5abcbb6b51de6" => "24/07/2018", "field_5abcbbb351de7" => "657", "field_5abcbbb651de8" => "24/07/2018", "field_5abcbbb851de9" => "15", "field_5abcbbbb51dea"=> "yes" ) ) ); array_walk_recursive( $array, function (&$value) { if (preg_match('/^\d[1-9]\/[1-9][0-9][0-9][0-9]$/',$value)) { $value = '01/' . $value; } } ); var_dump($array);