多级数组遍历问题

PHP新手请教各位一个问题，现已通过递归从数据库中抓出来一个员工的所有下属（包括下属的下属），print_r ($sub)效果如下：

Array(    [0] => User Object        (            [userId] => 365            [name] => aa            [cn_name] => 王A            [job] => A区域销售工程师            [rep_id] => 368            [sub] => Array                (                )        )    [1] => User Object        (            [userId] => 367            [name] => cc            [cn_name] => 王C            [job] => A区域销售主管            [rep_id] => 368            [sub] => Array                (                    [0] => User Object                        (                            [userId] => 379                            [name] => mm                            [cn_name] => 黄XX                            [job] => 销售工程师                            [rep_id] => 367                            [sub] => Array                                (                                    [0] => User Object                                        (                                            [userId] => 381                                            [name] => abc                                            [cn_name] => 张abc                                            [job] => 销售工程师                                            [rep_id] => 379                                            [sub] => Array                                                (                                                )                                        )                                )                        )                    [1] => User Object                        (                            [userId] => 380                            [name] => xxxx                            [cn_name] => 张XX                            [job] => 销售工程师                            [rep_id] => 367                            [sub] => Array                                (                                )                        )                )        ))

现在的需求是，写一个函数，遍历这个多级数组，然后生成一个新的一维数组，类似这样：

Array(    [0] => User Object        (            [userId] => 365            [name] => aa            [cn_name] => 王A            [job] => A区域销售工程师            [rep_id] => 368        )    [1] => User Object        (            [userId] => 367            [name] => cc            [cn_name] => 王C            [job] => A区域销售主管            [rep_id] => 368        )    [2] => User Object        (            [userId] => 379            [name] => mm            [cn_name] => 黄XX            [job] => 销售工程师            [rep_id] => 367        )    [3] => User Object        (            [userId] => 381            [name] => abc            [cn_name] => 张abc            [job] => 销售工程师            [rep_id] => 379        )    [4] => User Object        (            [userId] => 380            [name] => xxxx            [cn_name] => 张XX            [job] => 销售工程师            [rep_id] => 367         ))

感觉这是数组的基本应用，但是一下脑子短路了，半天没搞出来，所以求教各位，希望各位大神赐教，拜谢！

回复讨论(解决方案)

都下班过节去了么？苦逼的还要加班。。

用foreach(xxx as key=>value)读，新的数组赋值。

用foreach(xxx as key=>value)读，新的数组赋值。

这个只能读到第一级元素，第二级以后的就会丢掉了。。

递归产生的，当然也要递归降维

递归产生的，当然也要递归降维

恩是的，还是要用递归和全局变量才行，已经搞定了，谢谢