具有多个叶节点的PHP Flatten Array

Question

What is the best way to flatten an array with multiple leaf nodes so that each full path to leaf is a distinct return?

array("Object"=>array("Properties"=>array(1, 2)));

to yield

1. Object.Properties.1
2. Object.Properties.2

I'm able to flatten to Object.Properties.1 but 2 does not get processed with recursive function:

function flattenArray($prefix, $array)
{
    $result = array();
    foreach ($array as $key => $value)
    {
        if (is_array($value))
            $result = array_merge($result, flattenArray($prefix . $key . '.', $value));
        else
            $result[$prefix . $key] = $value;
    }   
    return $result;
}

I presume top down will not work when anticipating multiple leaf nodes, so either need some type of bottom up processing or a way to copy array for each leaf and process (althought that seems completely inefficient)

Answer 1

function flatten(array $data, $separator = '.') {
  $result = array();
  $stack = array();
  $path = null;

  reset($data);
  while (!empty($data)) {
    $key = key($data);
    $element = $data[$key];
    unset($data[$key]);  
    if (is_array($element)) {
      if (!empty($data)) {
        $stack[] = array($data, $path);
      }
      $data = $element;
      $path .= $key . $separator;
    } else {
      $result[$path . $key] = $element;
    }

    if (empty($data) && !empty($stack)) {
      list($data, $path) = array_pop($stack);
    }
  }
  return $result;
}

var_dump(flatten(array("Object"=>array("Properties"=>array(1, 2)))));

Output:

array(2) {
  ["Object.Properties.0"]=>
  int(1)
  ["Object.Properties.1"]=>
  int(2)
}