Функция implode и многомерный массив

function multi_implode($sep, $array)
{
$_array = array();

foreach($array as $val)
{
if(is_array($val)) $_array[] = multi_implode($sep, $val);
else $_array[] = $val;
}

return implode($sep, $_array);
}

function multi_implode($sep, $array) {
foreach($array as $val)
$_array[] = is_array($val)? multi_implode($sep, $val) : $val;
return implode($sep, $_array);
}