PHP Laravel 5.5集合变平并保留整数键？

Question

我有以下数组：

$array = [
    '2' => ['3' => ['56' => '2'], '6' => ['48' => '2']],
    '4' => ['4' => ['433' => '2', '140' => '2'], '8' => ['421' => '2', '140' => '2']],
    '5' => ['5' => ['88' => '4', '87' => '2']]
];

以下代码（拼合）应通过保留键返回，但不是吗？

collect($array)->flatten(1);

应该给我

[
    '3' => ['56' => '2'],
    '6' => ['48' => '2'],
    '4' => ['433' => '2', '140' => '2'],
    '8' => ['421' => '2', '140' => '2'],
    '5' => ['88' => '4', '87' => '2']
]

但是它丢失了密钥，只给出了数组结果：/我使用错了吗？我应该如何展平和保存密钥？

Answer 1

一个不错的解决方案是使用mapWithKeys方法。这将使数组变平并保留键：

collect($array)->mapWithKeys(function($a) {
    return $a;
});

该mapWithKeys方法遍历集合并将每个值传递给给定的回调。回调应返回一个包含单个键/值对的关联数组