Searching for key in multidimensional array and returning path to it

Question

I need to find a specific key in an array, and return both its value and the path to find that key. Example:

$array = array(
  \'fs1\' =>         


        

Answer 1

Just for completion sake and future visitors. Combining the example code above and the answer I commented about to get the keys. Here is a working function that will return the requested results with one small change. In my return array I return the keys path and value instead of the requested 0 and $search for the keys. I find this more verbose and easier to handle.

 array(
        'id1' => 0,
        'foo' => 1,
        'fs2' => array(
            'id2' => 1,
            'foo2' => 2,
            'fs3' => array(
                'id3' => null,
            ),
            'fs4' => array(
                'id4' => 4,
                'bar' => 1,
            ),
        ),
    ),
);

function search($array, $searchKey=''){
    //create a recursive iterator to loop over the array recursively
    $iter = new RecursiveIteratorIterator(
        new RecursiveArrayIterator($array),
        RecursiveIteratorIterator::SELF_FIRST);

    //loop over the iterator
    foreach ($iter as $key => $value) {
        //if the key matches our search
        if ($key === $searchKey) {
            //add the current key
            $keys = array($key);
            //loop up the recursive chain
            for($i=$iter->getDepth()-1;$i>=0;$i--){
                //add each parent key
                array_unshift($keys, $iter->getSubIterator($i)->key());
            }
            //return our output array
            return array('path'=>implode('.', $keys), 'value'=>$value);
        }
    }
    //return false if not found
    return false;
}

$searchResult1 = search($array, 'fs2');
$searchResult2 = search($array, 'fs3');
echo "
";
print_r($searchResult1);
print_r($searchResult2);


outputs: 

Array
(
    [path] => fs1.fs2
    [value] => Array
        (
            [id2] => 1
            [foo2] => 2
            [fs3] => Array
                (
                    [id3] => 
                )

            [fs4] => Array
                (
                    [id4] => 4
                    [bar] => 1
                )

        )

)
Array
(
    [path] => fs1.fs2.fs3
    [value] => Array
        (
            [id3] => 
        )

)