PHP数组操作冗长低效？seboettg/collection助你优雅处理复杂数据！

<code class="bash">composer require seboettg/collection</code>

<code class="php">require 'vendor/autoload.php';</code>

<code class="php">use function Seboettg\Collection\Lists\listOf;
use function Seboettg\Collection\Lists\listFromArray;
use function Seboettg\Collection\Lists\emptyList;

// 创建一个简单列表
$list = listOf("a", "b", "c", "d");
print_r($list);

// 从现有数组创建列表
$array = ["d", "e", "f"];
$otherList = listFromArray($array);

// 创建一个空列表
$emptyList = emptyList();
echo $emptyList->count(); // 输出：0</code>

<code class="php">$numbers = listOf(1, 2, 3, 4, 5);

// 将每个数字立方
$cubicNumbers = $numbers->map(fn ($i) => $i * $i * $i);
// 结果：[1, 8, 27, 64, 125]

// 筛选出奇数
$oddNumbers = $numbers->filter(fn($number) => $number % 2 !== 0);
// 结果：[1, 3, 5]</code>

<code class="php">use Seboettg\Collection\Map\Pair;
use function Seboettg\Collection\Map\pair;
use function Seboettg\Collection\Map\mapOf;
use function Seboettg\Collection\Map\emptyMap;

// 通过 Pair 对象创建映射
$map = mapOf(
    pair("Ceres", "Giuseppe Piazzi"),
    pair("Pallas", "Heinrich Wilhelm Olbers")
);
print_r($map);

// 创建空映射
$emptyMap = emptyMap();
echo $emptyMap->count(); // 输出：0</code>

<code class="php">$asteroidExplorerMap = mapOf(
    pair("Ceres", "Giuseppe Piazzi"),
    pair("Pallas", "Heinrich Wilhelm Olbers"),
    pair("Juno", "Karl Ludwig Harding"),
    pair("Vesta", "Heinrich Wilhelm Olbers")
);

echo $asteroidExplorerMap->get("Juno"); // 输出：Karl Ludwig Harding
echo $asteroidExplorerMap["Pallas"]; // 也可以像数组一样访问

$keys = $asteroidExplorerMap->getKeys(); // 获取所有键的列表
$values = $asteroidExplorerMap->values()->distinct(); // 获取所有不重复的值的列表

$asteroidExplorerMap->put("Iris", "J. R. Hind"); // 添加或更新元素
$asteroidExplorerMap->remove("Juno"); // 移除元素</code>

<code class="php">class Asteroid {
    public string $name;
    public ?string $explorer;
    public function __construct(string $name, string $explorer) {
        $this->name = $name;
        $this->explorer = $explorer;
    }
}

// 将映射中的键值对转换为 Asteroid 对象列表
$asteroids = $asteroidExplorerMap
    ->map(fn (string $key, string $value): Asteroid => new Asteroid($key, $value));

// 过滤掉键为 "Juno" 的条目
$filteredMap = $asteroidExplorerMap->filter(fn (string $key, string $value): bool => $key !== "Juno");</code>

<code class="php">use Seboettg\Collection\Stack;

$stack = new Stack();
$stack->push("a")->push("b")->push("c");

echo $stack->pop(); // 输出 c
echo $stack->count(); // 输出 2
echo $stack->peek(); // 输出 b (不移除)</code>

<code class="php">use Seboettg\Collection\Queue;

$queue = new Queue();
$queue->enqueue("d")->enqueue("z")->enqueue("b");

echo $queue->dequeue(); // 输出 d
echo $queue->dequeue(); // 输出 z</code>

<code class="json">[
   {
       "id": "A001",
       "lastname": "Doe",
       "firstname": "John",
       "createDate": "2022-06-10 09:21:12"
   },
   {
       "id": "A002",
       "lastname": "Doe",
       "firstname": "Jane",
       "createDate": "2022-06-10 09:21:13"
   },
   {
       "id": "A004",
       "lastname": "Mustermann",
       "firstname": "Erika",
       "createDate": "2022-06-11 08:21:13"
   }
]</code>

<code class="php">use function Seboettg\Collection\Lists\listFromArray;

class Customer {
    public string $id;
    public string $lastname;
    public string $firstname;
    public DateTime $createDate;
    public function __construct(string $id, string $lastname, string $firstname, DateTime $createDate) {
        $this->id = $id;
        $this->lastname = $lastname;
        $this->firstname = $firstname;
        $this->createDate = $createDate;
    }
}

// 1. 从 JSON 文件加载数据并转换为 List
$customerList = listFromArray(json_decode(file_get_contents("customer.json"), true));

// 2. 链式操作：筛选、映射和关联
$customerMap = $customerList
    ->filter(fn (array $customerArray) => $customerArray["lastname"] === "Doe") // 筛选出姓氏为 "Doe" 的客户
    ->map(fn (array $customerArray) => new Customer( // 将数组映射为 Customer 对象
        $customerArray["id"],
        $customerArray["lastname"],
        $customerArray["firstname"],
        DateTime::createFromFormat("Y-m-d H:i:s", $customerArray["createDate"])
     ))
    ->associateBy(fn(Customer $customer) => $customer->id); // 以客户ID作为键，将 Customer 对象关联起来

print_r($customerMap);</code>

<code>Seboettg\Collection\Map\MapInterface@anonymous Object
(
    [array:Seboettg\Collection\Map\MapInterface@anonymous:private] => Array
        (
            [A001] => Customer Object (...) // John Doe
            [A002] => Customer Object (...) // Jane Doe
        )
)</code>

<code class="php">// 假设 $customerService 是一个服务，提供 getById 方法
$listOfIds = listOf("A001", "A002", "A004");
$customerMap = $listOfIds
    ->associateWith(fn ($customerId) => $customerService->getById($customerId)); // 根据每个ID获取客户对象并关联</code>