Recursively traverses a multidimensional array in search of a specific key and returns an array containing the keys that correspond to the path of the first found instance, or an empty array on failure.

recursive-multidimensional-array-search-by-key.php

<?php

/**
 * Recursively traverses a multidimensional array in search of a specific key and returns an
 * array containing the keys that correspond to the path of the first found instance, or an
 * empty array on failure.
 */
function recursive_multidimensional_array_search_by_key( $key, array $data, $stack = array() ) {
	if( array_key_exists( $key, $data ) ) {
		array_push( $stack, $key );
		return $stack;
	}
	foreach ( $data as $k => $v ) {
		if( is_array( $v ) ) {
			array_push( $stack, $k );
			$found = call_user_func( __FUNCTION__, $key, $v, $stack );
			if( $found ) {
				return $found;
			}
			array_pop( $stack );
		}
	}
	return false;
}

Thanks a lot! Saved my day. After my approach failed and some investigation, I could ask the proper question and found your solution.

Awesome!