PHP数组排序问题

Question

$array = [ ['num'=>22,'time'=>'2017-10-23','name'=>'小王'], ['num'=>22,'time'=>'2017-10-21','name'=>'小白'], ['num'=>123,'time'=>'2017-09-23','name'=>'小李'], ['num'=>456,'time'=>'2017-10-23','name'=>'小黑'], ['num'=>123,'time'=>'2017-09-28','name'=>'小猪'], ['num'=>298,'time'=>'2017-10-23','name'=>'小狗'] ]; 按下标num倒序排列， num一样的按time升序。。 各位老哥。有什么好的办法或者思路吗？

Answer 1

核心代码就大概是这个样子了，没有考虑时间是字符串的问题，你将就看一下改一改吧

 $array = [
              ['num'=>22,'time'=>'2017-10-23','name'=>'小王'],
              ['num'=>22,'time'=>'2017-10-21','name'=>'小白'],
              ['num'=>123,'time'=>'2017-09-23','name'=>'小李'],
              ['num'=>456,'time'=>'2017-10-23','name'=>'小黑'],
              ['num'=>123,'time'=>'2017-09-28','name'=>'小猪'],
              ['num'=>298,'time'=>'2017-10-23','name'=>'小狗']
            ];


function cmp($a, $b)
{
    if ($a['num'] == $b['num']) {
        return $a['time']<$b['time'] ? -1 : 1;
    }
    return ($a['num'] > $b['num']) ? -1 : 1;
}

usort($array, "cmp");

var_dump ($array);