PHP Laravel 5.5 集合展平并保留整数键？

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']]
];

下面的代码（扁平化）应该 return 它通过保留键，但它没有？

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']
]

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

Answer 1

您不能在此处使用 flatten()。我没有一个优雅的解决方案，但我已经测试过它并且它非常适合您的阵列：

foreach ($array as $items) {
    foreach ($items as $key => $item) {
        $newArray[$key] = $item;
    }
}

dd($newArray);

Answer 2

一个优雅的解决方案是使用 mapWithKeys 方法。这将使您的数组变平并保留键：

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

The mapWithKeys method iterates through the collection and passes each value to the given callback. The callback should return an associative array containing a single key / value pair

PHP Laravel 5.5 集合展平并保留整数键？

PHP Laravel 5.5 collections flatten and keep the integer keys?

php

flatten

collect

laravel