php - 使用字段值对数组数据进行分组

Question

我有一个数组新闻源，其中包含当前用户的最后一个关注者，如下所示：

$newsFeed=array(
1 => array(
'follower'=>'1',
'following'=>'5',
'datecreation'=>'2013-07-12 15:10:34'
),
2=>array(
'follower'=>'6',
'following'=>'5',
'datecreation'=>'2013-07-12 12:30:56'
),
3=>array(
'follower'=>'7',
'following'=>'5',
'datecreation'=>'2013-05-12 19:08:00'
)
);

我想要做的是缩短新闻提要，将同一天的项目放在一个数组中，即上表中的项目 1 和 2。如下：

 $newsFeed=array(
    1 => array(
    'follower'=>array('1','6'),
    'following'=>'5',
    'datecreation'=>'2013-07-12'
    ),
    3=>array(
    'follower'=>'7',
    'following'=>'5',
    'datecreation'=>'2013-05-12 19:08:00'
    )
    );

请注意，在结果中，我删除了 key=2 和 key=1 的数组，并将关注者的 id 放入一个数组中，然后放入一个新数组中。

是否有可以提供帮助的 PHP 函数？

Answer 1

最后，我找到了解决方案，这是一个建议的解决方案......将来可能会针对可能的错误或异常进行更多编辑。

这是我建议的解决方案

$creationDate1 = false;
        foreach ($newsFeed as $key => $feed) {

            /*             * **followers** */
            if ($feed['type'] == 'follow') { //test if the current row is a follow type
                $creationDate = DateTime::createFromFormat("Y-m-d H:i:s", $feed['creationdate']);
                $creationDate = $creationDate->format('Y-m-d'); //drop H:i:s from date

                if ($creationDate != $creationDate1) {  
                    $followKey = $key;
                    $followersArray = array();
                }


                $followersArray[] = $feed['follower']; //array for followers ids


                unset($newsFeed[$key]);//remove the current row

                if ($creationDate != $creationDate1) { // if follow has not the same date as the previous one


                    $newsFeed[$followKey] = array(
                        'follower' => $followersArray,
                        'following' => $feed['following'],
                        'creationdate' => $feed['creationdate']
                    );//add row, with the datetime
                } else { //add row, with date, and without time.
                    $newsFeed[$followKey] = array(
                        'follower' => $followersArray,
                        'following' => $feed['following'],
                        'creationdate' => $creationDate
                    );
                }

                $creationDate1 = $creationDate; //$creationDate1=date of the current row.
            }
        } 

任何改进，以及编辑或建议将不胜感激