多维数组按相似的键/值对分组

Question

我有一个多维数组，如下所示：

Array (
  [0] => Array (
    [date] => August
    [mozrank] => 2
    [domain_authority] => 41
    [external_links] => 9
    [unique_visitors] => 14
  )
  [1] => Array (
    [date] => August
    [post_count] => 70
    [comment_count] => 53
    [theme] => yes
    [plugins] => 3
  )
  [2] => Array (
    [date] => September
    [mozrank] => 4
    [domain_authority] => 42
    [external_links] => 10
    [unique_visitors] => 20
  )
  [3] => Array (
    [date] => September
    [post_count] => 71
    [comment_count] => 56
    [theme] => yes
    [plugins] => 5
  )
)

您会注意到，有两个数组具有相同的键/值对（八月）和两个数组具有相同的键/值对（九月）。 但是，在每种情况下，它们都有与之关联的不同密钥。 我试图将值相同的日期键上的每个数组分组，然后将其他键合并在一起。 例如，输出为：

Array (
  [0] => Array (
    [date] => August
    [mozrank] => 2
    [domain_authority] => 41
    [external_links] => 9
    [unique_visitors] => 14
    [post_count] => 70
    [comment_count] => 53
    [theme] => yes
    [plugins] => 3
  )
  [1] => Array (
    [date] => September
    [mozrank] => 4
    [domain_authority] => 42
    [external_links] => 10
    [unique_visitors] => 20
    [post_count] => 71
    [comment_count] => 56
    [theme] => yes
    [plugins] => 5
  )
)

有任何想法吗？

Answer 1

我想到的第一件事：

$merged = array();
foreach ($array as $item)
{
    $date = $item['date'];
    if (!isset($merged[$date]))
    {
        $merged[$date] = array();
    }
    $merged[$date] = array_merge($merged[$date], $item);
}

结果将有一个数组，其中key是一个月。 如果要使用标准索引（从0开始），则可以始终使用shuffle() 。

结果：

array (size=2)
  'August' => 
    array (size=9)
      'date' => string 'August' (length=6)
      'mozrank' => int 2
      'domain_authority' => int 41
      'external_links' => int 9
      'unique_visitors' => int 14
      'post_count' => int 70
      'comment_count' => int 53
      'theme' => string 'yes' (length=3)
      'plugins' => int 3
  'September' => 
    array (size=9)
      'date' => string 'September' (length=9)
      'mozrank' => int 4
      'domain_authority' => int 42
      'external_links' => int 10
      'unique_visitors' => int 20
      'post_count' => int 71
      'comment_count' => int 56
      'theme' => string 'yes' (length=3)
      'plugins' => int 5

PS我觉得可以做得比这更好...