php - 比较和打印数组中的相同值

Question

我想比较像下面这样的数组中的数据并合并相同的数据。

Array (    [0] => Array
       (
           [0] => 2019-10-21
           [1] => Remzi
       )

   [1] => Array
       (
           [0] => 2019-10-21
           [1] => Ahmet
      )

   [2] => Array
       (
           [0] => 2019-10-14
           [1] => Ali
       ) )

我想像这样得到 output ：

2019-10-21, Remzi - Ahmet (Same birtday) <br>
2019-10-14, Ali (different birtday)

我怎样才能做到这一点？

Answer 1

像这样做，

$birthday_dic = [];
foreach($birthdays as $birthday){
    $birthday_dic[$birthday[0]][] = $birthday[1];
}
$birthday_dic = array_map(function($v){return join(" - ",$v);},$birthday_dic);
print_r($birthday_dic);