我可以在php中获取多级关联数组的所有键吗

Question

在 php 中是否有任何方法可以获取 php 中多维数组的 n 级键？

这是我的关联数组，作为输出，我想要一个包含键 object_id 的所有值的数组，因为您可以从结构本身那里看到 object_id 有许多嵌套级别那么如何获取键 object_id 的所有值？

   array
  'cart' => 
    array
      12061 => 
        array
          'object_id' => string '12061' (length=5)
          'discriminator' => string 'SimpleProductOffering' (length=21)
          'spec' => 
            array
              100012061 => 
                array
                  'object_id' => string '100012061' (length=9)
                  'discriminator' => string 'CompositeProductSpecification' (length=29)
                  'trait' => 
                    array
                      'MAIN_CPE' => 
                        array
                          'object_id' => string '1000000000015' (length=13)
                          'is_configurable' => string '0' (length=1)
                          'trait_value' => 
                            array
                              10001 => 
                                array
                                  'object_id' => string '10001' (length=5)
                                  'collateral' => 
                                    array
                                      empty
                          'collateral' => 
                            array
                              empty
          'offer_type' => null
          'price' => 
            array
              12862 => 
                array
                  'object_id' => string '12862' (length=5)
                  'discriminator' => string 'RecurringChargeProdOfferPriceCharge' (length=35)
                  'price_alteration' => 
                    array
                      empty
                  'collateral' => 
                    array
                      empty
              12876 => 
                array
                  'object_id' => string '12876' (length=5)
                  'discriminator' => string 'RecurringChargeProdOfferPriceCharge' (length=35)
                  'price_alteration' => 
                    array
                      0 => string '12876' (length=5)
                      1 => string '12894' (length=5)
                  'collateral' => 
                    array
                      empty
          'contained_offers' => 
            array
              empty
          'family' => 
            array
              0 => string 'TV Subscription' (length=24)
          'relationship' => 
            array
              'CHILDREN' => 
                array
                  'object_id' => string '1206102000' (length=10)
                  'min' => string '0' (length=1)
                  'max' => string '1000000' (length=7)
                  'related_offer' => 
                    array
                      0 => string '10410' (length=5)
                      1 => string '10411' (length=5)
              'REQUIREMENTS' => 
                array
                  'object_id' => string '1206104000' (length=10)
                  'min' => string '1' (length=1)
                  'max' => string '1' (length=1)
                  'related_offer' => 
                    array
                      0 => string '11950' (length=5)
                      1 => string '11990' (length=5)
              'EXCLUSIONS' => 
                array
                  'object_id' => string '1206101000' (length=10)
                  'min' => string '1' (length=1)
                  'max' => string '1' (length=1)
                  'related_offer' => 
                    array
                      0 => string '12062' (length=5)
                      1 => string '12063' (length=5)
              'ALTERNATIVES' => 
                array
                  'object_id' => string '1206105000' (length=10)
                  'min' => string '1' (length=1)
                  'max' => string '1' (length=1)
                  'related_offer' => 
                    array
                      0 => string '12263' (length=5)
              'BUNDLE_ITEMS' => 
                array
                  'object_id' => string '1206106000' (length=10)
                  'min' => string '1' (length=1)
                  'max' => string '1' (length=1)
                  'related_offer' => 
                    array
                      0 => string '12062' (length=5)
          'financial_terms' => 
            array
              'billing_period' => 
                array
                  0 => string 'QUARTERLY' (length=9)
              'payment_method' => 
                array
                  0 => string 'DIRECT_DEBIT' (length=12)
              'bill_presentation' => 
                array
                  0 => string 'PAPER' (length=5)
          'contract_constraints' => 
            array
              'min_contract_period' => int 24
              'cancellation_period' => string 'ALWAYS' (length=6)
              'notice_period' => int 3
              'rollover_period' => int 2
              'right_of_wd_period' => int 1
          'collateral' => 
            array
              empty
      10017 => 
        array
          'object_id' => string '10017' (length=5)
          'spec' => 
            array
              100010017 => 
                array
                  'object_id' => string '100010017' (length=9)
                  'discriminator' => string 'CompositeProductSpecification' (length=29)
                  'trait' => 
                    array
                      empty
          'offer_type' => null
          'price' => 
            array
              300306 => 
                array
                  'object_id' => string '300306' (length=6)
                  'price_alteration' => 
                    array
                      empty
                  'collateral' => 
                    array
                      empty
              12894 => 
                array
                  'object_id' => string '12894' (length=5)
                  'discriminator' => string 'RecurringChargeProdOfferPriceCharge' (length=35)
                  'price_alteration' => 
                    array
                      empty
                  'collateral' => 
                    array
                      empty
              12862 => 
                array
                  'object_id' => string '12862' (length=5)
                  'discriminator' => string 'RecurringChargeProdOfferPriceCharge' (length=35)
                  'price_alteration' => 
                    array
                      empty
                  'collateral' => 
                    array
                      empty
              12876 => 
                array
                  'object_id' => string '12876' (length=5)
                  'discriminator' => string 'RecurringChargeProdOfferPriceCharge' (length=35)
                  'price_alteration' => 
                    array
                      0 => string '12876' (length=5)
                      1 => string '12894' (length=5)
                  'collateral' => 
                    array
                      empty
          'contained_offers' => 
            array
              0 => null
          'family' => 
            array
              empty
          'relationship' => 
            array
              'EXCLUSIONS' => 
                array
                  'object_id' => string '1001701000' (length=10)
                  'min' => string '1' (length=1)
                  'max' => string '1' (length=1)
                  'related_offer' => 
                    array
                      0 => string '11893' (length=5)
                      14 => string '12305' (length=5)
                      15 => string '12306' (length=5)
          'financial_terms' => 
            array
              'billing_period' => 
                array
                  0 => string 'MONTHLY' (length=7)
                  1 => string 'QUARTERLY' (length=9)
              'payment_method' => 
                array
                  0 => string 'DIRECT_DEBIT' (length=12)
                  1 => string 'DIRECT_DEBIT' (length=12)
              'bill_presentation' => 
                array
                  0 => string 'EMAIL' (length=5)
                  1 => string 'PAPER' (length=5)
          'contract_constraints' => 
            array
              'min_contract_period' => int 24
              'cancellation_period' => string 'ALWAYS' (length=6)
              'notice_period' => int 3
              'rollover_period' => int 2
              'right_of_wd_period' => int 1
          'collateral' => 
            array
              empty
  0 => 
    array
      11990 => 
        array
          'object_id' => string '11990' (length=5)
          'discriminator' => string 'SimpleProductOffering' (length=21)
          'spec' => 
            array
              100011990 => 
                array
                  'object_id' => string '100011990' (length=9)
                  'discriminator' => string 'CompositeProductSpecification' (length=29)
                  'trait' => 
                    array
                      empty
          'offer_type' => null
          'price' => 
            array
              12862 => 
                array
                  'object_id' => string '12862' (length=5)
                  'discriminator' => string 'RecurringChargeProdOfferPriceCharge' (length=35)
                  'price_alteration' => 
                    array
                      empty
                  'collateral' => 
                    array
                      empty
              12876 => 
                array
                  'object_id' => string '12876' (length=5)
                  'discriminator' => string 'RecurringChargeProdOfferPriceCharge' (length=35)
                  'price_alteration' => 
                    array
                      10017 => 
                        array
                          'object_id' => string '10017' (length=5)
                          'discriminator' => string 'RecurringChargeProdOfferPriceCharge' (length=35)
                          'price_alteration' => 
                            array
                              empty
                          'collateral' => 
                            array
                              empty
                      12894 => 
                        array
                          'object_id' => string '12894' (length=5)
                          'discriminator' => string 'RecurringChargeProdOfferPriceCharge' (length=35)
                          'price_alteration' => 
                            array
                              empty
                          'collateral' => 
                            array
                              empty
                  'collateral' => 
                    array
                      empty
          'contained_offers' => 
            array
              empty
          'family' => 
            array
              0 => string 'CATV' (length=4)
          'relationship' => 
            array
              empty
          'financial_terms' => 
            array
              'billing_period' => 
                array
                  0 => string 'QUARTERLY' (length=9)
              'payment_method' => 
                array
                  0 => string 'DIRECT_DEBIT' (length=12)
              'bill_presentation' => 
                array
                  0 => string 'PAPER' (length=5)
          'contract_constraints' => 
            array
              'min_contract_period' => int 24
          'collateral' => 
            array
              empty

输出应该是一个数组，其中包含keys = object_id的所有值。请指教？

Answer 1

我猜 Dereleased 的解决方案会更快（因为它使用内部循环），我的解决方案还可以处理 object_id 键的数组值。您的权衡；）

---

function find_all($needle, array $haystack, array &$result = null) {
    // This is to initialize the result array and is only needed for
    // the first call of this function
    if(is_null($result)) {
        $result = array();
    }
    foreach($haystack as $key => $value) {
        // Check whether the key is the value we are looking for. If the value
        // is not an array, add it to the result array.
        if($key === $needle && !is_array($value)) {
            $result[] = $value;
        }
        if(is_array($value)) {
            // If the current value is an array, we perform the same
            // operation with this 'subarray'.
            find_all($needle, $value, $result);
        }
    }
    // This is only needed in the first function call to retrieve the results
    return $result;
}

如您所见，结果数组将作为参考提供给函数的每次调用（由 & 表示）。这样，该函数的每次递归调用都可以访问相同数组，并且只需添加一个查找即可。

你可以这样做：

$values = find_all('object_id', $array);

它为我提供了你的数组：

Array
(
    [0] => 12061
    [1] => 100012061
    [2] => 1000000000015
    [3] => 10001
    [4] => 12862
    [5] => 12876
    [6] => 1206102000
    [7] => 1206104000
    [8] => 1206101000
    [9] => 1206105000
    [10] => 1206106000
    [11] => 10017
    [12] => 100010017
    [13] => 300306
    [14] => 12894
    [15] => 12862
    [16] => 12876
    [17] => 1001701000
    [18] => 11990
    [19] => 100011990
    [20] => 12862
    [21] => 12876
    [22] => 10017
    [23] => 12894
)

Answer 2

我的测试必须简单，因为我不会花时间将您提供的任何转储转换为工作数组；如果这不起作用，请提供数组的 var_export 用于测试目的。

然而，这听起来像是 array_walk_recursive()< 的工作/代码>。

$coll = array();

function array_get_keys($value, $key, $c) {
    if (strcasecmp($key,'object_id')==0) {
        array_push($c[0],$value);
    }
}

array_walk_recursive($array, 'array_get_keys', array(&$coll));

array_walk_recursive 的最后一个参数是数组中的引用，因为调用时传递引用已被弃用，这是唯一的方法（除了一些复杂的对象结构 参见下文）将对容器的引用传递给处理函数。

此代码应使用所有以“object_id”作为键的值填充 $coll。它不适用于“object_id”是数组的情况，因为这是 array_walk_recursive() 的已知行为（即，不会为本身就是数组的元素启动回调函数）。

编辑（为了正义）：

对象结构实际上并不那么复杂，所以如果您希望避免无关的数组/引用构造，请执行以下操作：

$coll = new ArrayObject;

function array_get_keys($value, $key, $c) {
    if (strcasecmp($key,'object_id')==0) {
        $c[] = $value;
    }
}

array_walk_recursive($array, 'array_get_keys', $coll);

工作原理

PHP 的 array_walk_recursive() 函数采用给定数组作为其第一个参数并迭代每个键/值对。如果值是标量，它将键/值组合传递给某个用户定义的回调函数；但是，如果该值是一个数组，则 array_walk_recursive() 将递归调用自身，并继续以相同的方式运行。它将以这种方式工作，直到循环遍历数组中的每个元素。

第二个参数是要使用的回调函数；在本例中，我编写并声明了一个函数 (array_get_keys)，并将其名称作为第二个参数中的字符串传递。因此，该函数由 array_walk_recursive() 是每次处理键/值对时执行的函数。

这两个示例中的第三个参数基本上是一段“额外”数据，我们可以传递给回调函数以改变其行为——在本例中，它是一个数组（或者在第二个示例中是一个 ArrayObject 容器），它是（ a) 在全局范围内定义，(b) 用于存储 $key == 'object_id' 为 true 的所有值。

在第一个示例中，我使用语法 array(&$coll) 来传递集合变量，因为这是传递对集合的引用以便可以在全局范围（否则，我们无法检索列表）。在第二个示例中，我将 $coll 声明为 ArrayObject，这使得它通过引用隐式传递，因此无需将其包含在数组中以确保它是在全局范围内修改。

Answer 3

使用 Spl 迭代器时，在 foreach 循环中检查 object_id 的替代方法：

class KeyFilter extends FilterIterator
{
    protected $acceptedKeys; // keys to return when iterating over the array

    public function __construct(array $keys, $iterator)
    {
        $this->acceptedKeys = $keys;
        parent::__construct($iterator);
    }

    public function accept()
    {
        // skip elements that return false when iterating
        return (in_array($this->key(), $this->acceptedKeys));
    }
}

扩展 FilterIterator 的子类必须实现 accept() 方法。在内部，当使用 foreach 迭代数组时，过滤器迭代器将调用您的 accept 方法并跳过该方法中编写的测试将返回 false 的任何元素。 FilterIterators 是可堆叠的，因此您可以将多个 FilterIterators 组合到一个 Filter Chain 中，这使得这是一种非常灵活的方法。

您可以像这样使用它

$yourArray = new KeyFilter(array('object_id' /* add more */),
                           new RecursiveIteratorIterator(
                               new RecursiveArrayIterator($yourArray)));

foreach($yourArray as $key => $value) {
    // will only return elements with an object_id key
    echo $key, '--', $value, PHP_EOL;
}

有关 SplIterators 的更多信息：

• http://www.phpro .org/tutorials/SPL 简介.html

Answer 4

基于@goat的回答，我写了一个小函数：

• 通过多维数组中的键查找值（无论级别如何）
• 排除空值
• 如果需要则删除重复项
• 如果为空函数则返回false

：

function array_find_recursive($arr, $key, $unique = false) {
    
    $res = false;

    foreach (new RecursiveIteratorIterator(new RecursiveArrayIterator($arr), RecursiveIteratorIterator::SELF_FIRST) as $k => $v) {
        if ($k === $key && $v != "") {
            $res[] = $v;
        }
    }
    
    if($unique)
        return array_unique($res);
    
    return $res;
}

使用而不管重复项：

$result = array_find_recursive($my_array, 'key');

使用排除重复项：

$result = array_find_recursive($my_array, 'my_key', true);

Answer 5

$res = array();
foreach (new RecursiveIteratorIterator(new RecursiveArrayIterator($arr), RecursiveIteratorIterator::SELF_FIRST) as $k => $v) {
    if ($k === 'object_id') {
        $res[] = $v;
    }
}