I have a class that contains a static array whose keys are strings and values ​​are arrays. If a specific array value exists, I want to get its key.

I thought the code using the array_search() function would accomplish this, but it fails to find the value and instead prints false. I thought the "strict" parameter might make a difference, but it doesn't seem to work. Did I do something wrong? What's the best way to write search code?

$ cat foo.php
<?php
class foo {
    static $name_to_bitnum = array(
        'Water Obstacle' => array('kind' => 'Facility', 'bitnum' => 5),
        'Driving' => array('kind' => 'Facility', 'bitnum' => 6),
        'Trails' => array('kind' => 'Facility', 'bitnum' => 7),
   );

    public static function bar($kind, $bitnum) {
        $search = array_search(array('kind' => $kind, 'bitnum' => $bitnum), self::$name_to_bitnum, $strict = false);
        // $search = array_search(self::$name_to_bitnum['Driving'], self::$name_to_bitnum, $strict = false);
        return $search;
    }
}
$foo = new foo();
echo var_dump($foo->bar('Driving', 6));
?>

$ php foo.php
C:xampp1826htdocsOSH0foo.php:21:
bool(false)

I noticed that if I uncommented the line of code and indexed into the array using the value of the array element I was looking for, then it succeeded and printed out the string (7) "Driving" . This doesn't seem right to me.