Php 如何合并两个数组的值？

我有两个阵列：

$a = array(
    array("id" => 132),
    array("id" => 131),
    array("id" => 129),
    array("id" => 128)
)

$b = array(
    array("id" => 129, "attachment_id" => 111),
    array("id" => 129, "attachment_id" => 112),
    array("id" => 132, "attachment_id" => 113),
    array("id" => 132, "attachment_id" => 114),
    array("id" => 132, "attachment_id" => 115)
)

我需要从这两个数组中创建一个数组<代码>id键必须是唯一的，因此不能重复。问题是：我需要在名为

attachments

的新数组中创建新元素，该数组包含该

id

的

attachment\u id

值。您知道，对于

id

，可能有多个

附件\u id

这很难解释，但我希望你能理解！谢谢你的建议

编辑：

以下是期望的结果：

$c = array(
    array("id" => 132, 'attachments' => array(113, 114, 115)),
    array("id" => 131, 'attachments' => array()),
    array("id" => 129, 'attachments' => array(111, 112)),
    array("id" => 128, 'attachments' => array())
);

---

按“id”为数组编制索引，然后使用

按“id”为数组编制索引，然后使用类似的方法：

# Temporary array
$c = array();

# Loop through all attachments and index them by id
foreach($b as $row) {
    if(!isset($c[$row['id']])) {
        $c[$row['id']] = array();
    }
    $c[$row['id']][] = $row['attachment_id'];
}

# Loop through ids and add attachments where available
foreach($a as &$row) {
    $row['attachments'] = isset($c[$row['id']]) ? $c[$row['id']] : array()
} unset($row);

输出：

array(
    array("id" => 132, "attachments" => array(113, 114, 115)),
    array("id" => 131, "attachments" => array()),
    array("id" => 129, "attachments" => array(111, 112)),
    array("id" => 128, "attachments" => array())
)

---

像这样的东西应该可以做到：

# Temporary array
$c = array();

# Loop through all attachments and index them by id
foreach($b as $row) {
    if(!isset($c[$row['id']])) {
        $c[$row['id']] = array();
    }
    $c[$row['id']][] = $row['attachment_id'];
}

# Loop through ids and add attachments where available
foreach($a as &$row) {
    $row['attachments'] = isset($c[$row['id']]) ? $c[$row['id']] : array()
} unset($row);

输出：

array(
    array("id" => 132, "attachments" => array(113, 114, 115)),
    array("id" => 131, "attachments" => array()),
    array("id" => 129, "attachments" => array(111, 112)),
    array("id" => 128, "attachments" => array())
)

比如：

$a = array(
    array("id" => 132),
    array("id" => 131),
    array("id" => 129),
    array("id" => 128)
);

$b = array(
    array("id" => 129, "attachment_id" => 111),
    array("id" => 129, "attachment_id" => 112),
    array("id" => 132, "attachment_id" => 113),
    array("id" => 132, "attachment_id" => 114),
    array("id" => 132, "attachment_id" => 115)
);

$c = array();

foreach ($a as $idEntry) {
    $tmp = array(
        'id' => $idEntry['id'],
        'attachments' => array()
    );

    foreach ($b as $bIdx => $attachmentEntry) {
        if ($attachmentEntry['id'] == $idEntry['id']) {
            $tmp['attachments'][] = $attachmentEntry['attachment_id'];
            unset($b[$bIdx]);
        }
    }

    $c[] = $tmp;
}

print_r($c);

比如：

$a = array(
    array("id" => 132),
    array("id" => 131),
    array("id" => 129),
    array("id" => 128)
);

$b = array(
    array("id" => 129, "attachment_id" => 111),
    array("id" => 129, "attachment_id" => 112),
    array("id" => 132, "attachment_id" => 113),
    array("id" => 132, "attachment_id" => 114),
    array("id" => 132, "attachment_id" => 115)
);

$c = array();

foreach ($a as $idEntry) {
    $tmp = array(
        'id' => $idEntry['id'],
        'attachments' => array()
    );

    foreach ($b as $bIdx => $attachmentEntry) {
        if ($attachmentEntry['id'] == $idEntry['id']) {
            $tmp['attachments'][] = $attachmentEntry['attachment_id'];
            unset($b[$bIdx]);
        }
    }

    $c[] = $tmp;
}

print_r($c);

---

@daGrevis“几乎”是因为？？）请看我的问题的编辑。结果不是我想要的；（@daGrevis，也许你错过了，但我的回答给出了你想要的结果。我自己修复了。

$attachmentEntry['id']

必须是

$attachmentEntry['attachment\u id']]

。有没有什么无痛的方法也可以将

$a

的其他元素添加到

$c

？@daGrevis“几乎”是因为？？？）请看我的问题的编辑。结果不是我想要的；（@daGrevis，也许你没有看到，但我的答案给出了你想要的结果。我自己修复了。

$attachmentEntry['id']

必须是

$attachmentEntry['attachment\u id']]

。是否有任何轻松的方法也可以将

$a

的其他元素添加到

$c

？