PHP递归重新排序无限级分类数组

public static  function Menus($id,$spac=0){ /*   $data = array( 1 => array('id' => 1,'name' => 'name1','pid' => 0),
        2 => array('id' => 2,'name' => 'name2','pid' => 0),
        3 => array('id' => 3,'name' => 'name3','pid' => 1),
        4 => array('id' => 4,'name' => 'name4','pid' => 0),
        5 => array('id' => 5,'name' => 'name5','pid' => 3),
        6 => array('id' => 6,'name' => 'name6','pid' => 3),
    );*/
     $menu = Menu::model()->findAll();    $arr = array();
    //  $arr = array_push($arr,$arr);
    foreach ($menu as $k => $v) {
        if ($v['parent_id'] == $id) {
            //  $arr[] = $v;
            //$v['id'] =str_repeat(' ',$spac) .$v['name'];
        //    $str .= "<option value='" . $v['id'] . "'>" . str_repeat("&nbsp;",$spac) . "|--" . $v['name'] . "</option>";
         //  self::Menus($v['id'],$spac);
            $arr[] = $v;
            $arr = array_merge($arr,self::Menus($v['menu_id']));  //递归合并数组        }    }
   // print_r($arrs);
    return $arr;
}