Get first parent key of value from Multidimensional Array in PHP

Question

How to get the first parent key of value from Multidimensional Array in PHP

Sample Code :

$arr = array(
    "a" => array("1"=>"!","2"=>"@","3"=>"#"),
    "b" => array("4"=>"$","5"=>"%","6"=>"^"),
    "c" => array("7"=>"&","8"=>"*","9"=>"(")
);

echo array_search("%",$arr);

Require Output: b

Answer 1

You can filter the array returning only the array(s) that contain what you are searching for and get the key:

echo key(array_filter($arr, function($v) { return array_search("%", $v); }));

Obviously if it is found in more than one array you will have to decide which key you want. The above will give you the first key.