php recursive array search - return specific parent

Question

I have an array that can vary in its dimension, sometimes can be small, sometimes can go deeper. I'm trying to search for a particular element in the array and if it is found, I would like to get a specific parent. So for instance, if I have an array as:

Again, the dimension can change, however, I'm looking for the the most outer parent's key that has siblings. ( in this case )

Array (
  [0] => Array (
    [0] => Array (              
        [0] => Array (         <<----------------------------------------+
              [0] => FOO0                                                |  
              [1] => BAR0         //Search BAR0 returns parent key 0     +
              [2] => Array(                                              |
                    [0] => HELLO0                                        |
                    [1] => BYE0   //Search BYE0 returns parent key 0     +
                  )                                                      |
              [3] => FOO0                                                |
              [4] => Array (                                             |
                    [0] => HELLO0  //Search HELLO0 returns parent key 0 --
                  )
            )
        [1] => Array (         <<----------------------------------------+
              [0] => FOO1                                                |
              [1] => BAR1                                                |
              [2] => Array (                                             |
                    [0] => HELLO1                                        |
                    [1] => BYE1                                          |
                  )                                                      |
              [3] => BASE1                                               |
              [4] => Array (                                             |
                    [0] => BAZ1                                          |
                    [1] => Array (                                       | 
                          [0] => DOO1 //Search DOO1 returns parent key 1 +
                          [1] => BOB2 //Search BOB2 returns parent key 1 +
                        )
                )
          )
        [2] => FOO2 // Search FOO2 returns key 2 (itself)
        )
    )
)

Sample Output for FOO2

[2] => FOO2 // searched value

I would really appreciate some help! Thanks!

Answer 1

I'm not completely sure this is what you are looking for, but you can give it a try:

function find($needle, array $haystack)
{
  foreach ($haystack as $i => $x) {
    if (is_array($x)) {
      $b = find($needle, $x);
      if ($b) return count($haystack) > 1 ? array($i, $x) : $b;
    }
    else if ($x == $needle) {
      return array($i, $x);
    }
  }

  return false;
}

list($key, $val) = find('FOO1', $data);

This doesn't return the exact element, but a copy of it. If you want the original item, it will need to be updated to use references.

You can change array($i, $x) to array($i => $x) in both places if you don't want to use the list construct when querying the function. But I think it's easier to work with as it is written.

Answer 2

function recursive_array_search($k,$h) {
    foreach($h as $key=>$v) if($k===$v OR (is_array($v) && recursive_array_search($k,$v) !== false)) return $key;
    return false;
}

Usage:

echo recursive_array_search($searchThis, $InThisArray);

Now you just have to modify this to return whatever you want.

Source: php.net