PHP multi-dimensional array to string and multi-dimensional array to one-dimensional array code

/**
* @method Multidimensional array to string
* @staticvar array $result_array
* @param type $array
* @return type
* @link bbs.it-home.org
*/
function arrayToString($arr)
{
if (is_array($arr))
{
return implode(',', array_map('arrayToString', $arr));
}
return $arr;
}
/**
* @method Multidimensional array becomes one-dimensional array
* @staticvar array $result_array
* @param type $array
* @return type
* @link bbs.it-home.org
*/
function multi2array($array) {
static $result_array = array();
foreach ($array as $key => $value) {
if (is_array($value)) {
array_multi2array($value);
}
else
$result_array[$key] = $value;
}
return $result_array;
}