Question

Possible Duplicate:
PHP Walk through multidimensional array while preserving keys

I have a deep array like this one:

array {
  ["key1"] => "A"
  ["key2"] => "B"
  ["key3"] => array {
                ["subkey1"] => "C"
                ["subkey2"] => array {
                                  ["subsubkey1"] => "D"
                               }
              }

}

I don’t know how deep this array will get.
Now I want to convert it to an array that looks like this:

array {
   array {
  ["key1"] => "A"
  ["key2"] => "B"
  ["key3.subkey1"] => "C"
  ["key3.subkey2.subsubkey1"] = > "D"
}

How would I do that? I guess it needs a recursion?

Answer 1

As simple as

$array = array(
    'a' => array(
        'b' => array(
            'c' => 'val'
        ),
        'd' => 'val2'
    ),
    'e' => 'val3'
);

var_dump(collapse($array));

function collapse($array)
{
    $result = array();
    foreach ($array as $key => $val) {
        if (is_array($val)) {
            foreach (collapse($val) as $nested_key => $nested_val) {
                $result[$key . '.' . $nested_key] = $nested_val;
            }
        } else {
            $result[$key] = $val;
        }
    }

    return $result;
}

http://ideone.com/ieSZ6

PS: usually I don’t like to give complete solutions, but in this case – the solution might be too difficult for newbie