PHP如何将数组组织成组但保持顺序？

我想通过

id

，
但仍然保留订单，这意味着它可能有重复的组， 比如：

数组：

array (
  0 => 
  array (
    'id' => 1,
    'message' => 'AAA',
    'sent_on' => 1582097767
  ),

  1 => 
  array (
    'id' => 2,
    'message' => 'AAAQAW',
    'sent_on' => 1582097770
  ),

  2 => 
  array (
    'id' => 2,
    'message' => 'dqwdq',
    'sent_on' => 1582097772
  ),

  3 => 
  array (
    'id' => 1,
    'message' => 'dqwdq',
    'sent_on' => 1582097773
  ),

  4 => 
  array (
    'id' => 1,
    'message' => 'wq',
    'sent_on' => 1582097773
  ),

  5 => 
  array (
    'id' => 2,
    'message' => 'd',
    'sent_on' => 1582097774
  ),

  6 => 
  array (
    'id' => 1,
    'message' => 'dew',
    'sent_on' => 1582112219
  )
)

希望的结果：

array (
    0 => 
    array (
        0 => 
        array (
          'id' => 1,
          'message' => 'AAA',
          'sent_on' => 1582097767

        ),
    ),

    1 => 
    array (
        0 => 
        array (
          'id' => 2,
          'message' => 'AAAQAW',
          'sent_on' => 1582097770

        ),
        1 => 
        array (
          'id' => 2,
          'message' => 'dqwdq',
          'sent_on' => 1582097772

        )
    ),

    2 => 
    array (
        0 => 
        array (
          'id' => 1,
          'message' => 'dqwdq',
          'sent_on' => 1582097773

        ),
        1 => 
        array (
          'id' => 1,
          'message' => 'wq',
          'sent_on' => 1582097773

        )
    ),

    3 => 
    array (
        0 => 
        array (
          'id' => 2,
          'message' => 'd',
          'sent_on' => 1582097774

        )
    ),

    4 => 
    array (
        0 => 
        array (
          'id' => 1,
          'message' => 'dew',
          'sent_on' => 1582112219

        )
    )
)

---

是的，使用

array\u reduce

可以很容易地完成：

$lastCheckedItem = ['id' => 0];

$finalArray = array_reduce($array, static function(array $carry, array $item) use (&$lastCheckedItem) {
    if ($lastCheckedItem['id'] === $item['id'] && !empty($carry)) {
        $lastKey = array_key_last($carry);
        $carry[$lastKey][] = $item;
    }
    else {
        $carry[] = [$item];
    }

    $lastCheckedItem = $item;

    return $carry;
}, []);

---

aa还有什么问题？@matit呃，是的，我只知道如何将数组分成两组，如

id=1

，

id=2

，但我希望它需要有五组谢谢！！！很好的回答！！顺便问一下，为什么数组名是

$carry

lolyw。因为它在每次迭代中都会带上设定的值，直到循环结束。明白了。它让我笑了，因为它是我爸爸给我的英文昵称。。自从你问起我就注意到了：）

$lastCheckedItem = ['id' => 0];

$finalArray = array_reduce($array, static function(array $carry, array $item) use (&$lastCheckedItem) {
    if ($lastCheckedItem['id'] === $item['id'] && !empty($carry)) {
        $lastKey = array_key_last($carry);
        $carry[$lastKey][] = $item;
    }
    else {
        $carry[] = [$item];
    }

    $lastCheckedItem = $item;

    return $carry;
}, []);