求解数组合并解决方案

求解数组合并
Array ( [59] =>aa [17] => bb [18] =>cc [69] => dd [21] =>ee [22] => ss [23] => Array ( [0] => 1a[1] =>2a[2] => 3a [3] =>4a [4] => 55 ) [24] =>vv [26] => va [43] => Array ( [0] => 道 [1] =>向 [2] => 圾 [3] => 灯 [4] => 速 [5] => 灯 [6] => 则 ) [53] => 元 [54] => 995 )[1]=>Array ( [59] =>aa [17] => bb [18] =>cc [69] => dd [21] =>ee [22] => ss [23] => Array ( [0] => 1a[1] =>2a[2] => 3a [3] =>4a [4] => 55 ) [24] =>vv [26] => va [43] => Array ( [0] => 道 [1] =>向 [2] => 圾 [3] => 灯 [4] => 速 [5] => 灯 [6] => 则 ) [53] => 元 [54] => 995 )
如何将最后一维合并？
是用foreach遍历时合并吗？如果数据多了会不会卡住？
------解决方案--------------------

foreach($arr as $k=>$v){
        if(is_array($v)) $arr[$k] = implode(',', $v);
}
print_r($arr);

------解决方案--------------------
不一定，需判断 $v 是数组后，方可进入 foeach($v as ...