创建一个新数组，其键作为旧数组的值，总计数？

Question

我有一个包含以下值的数组。我正在尝试使用数组 php 数组函数创建一个新数组，并尽量避免使用 foreach。我们用于新数组的键是“status”，根据状态我们为每个邮件 ID 创建新数组。

<?php
[
    {
        "mail_id": "29848947",
        "last_name": "Doe",
        "first_name": "Jon",
        "email": "jdoe@gmail.com",
        "status": "opened"
    },
    {
        "mail_id": "340980398",
        "last_name": "Doe",
        "first_name": "Jane",
        "email": "janedoe@gmail.com",
        "status": "sent"
    },
    {
        "mail_id": "877586",
        "last_name": "Dwaye",
        "first_name": "Jhon",
        "email": "Jhondw@yahoo.com",
        "status": "clicked"
    },
    {
        "mail_id": "225253463",
        "last_name": "Doe",
        "first_name": "Jon",
        "email": "jdoe@gmail.com",
        "status": "opened"
    },
    {
        "mail_id": "849849w4",
        "last_name": "Doe",
        "first_name": "Jane",
        "email": "janedoe@gmail.com",
        "status": "sent"
    }
]
?>

结果或新数组如下。我正在尝试使用任何数组函数（如 array_walk_recursive 或 array_reduce）来实现以下结果，使代码看起来既美观又紧凑。

<?php
 [
    [
            "first_name": "Jon",
            "last_name": "Doe",
            "email": "jdoe@gmail.com",
            "opened": 2,
            "blocked": 0,
            "hard_bounced": 0,
            "soft_bounced": 0,
            "received": 0,
            "clicked": 0
    ],
    [
            "first_name": "Jane",
            "last_name": "Doe",
            "email": "janedoe@gmail.com",
            "opened": 0,
            "blocked": 0,
            "hard_bounced": 0,
            "soft_bounced": 0,
            "sent": 2,
            "clicked": 0
    ],
    [
        "first_name": "Jhon",
        "last_name": "Dwaye",
        "email": "Jhondw@yahoo.com",
        "opened": 0,
        "blocked": 0,
        "hard_bounced": 0,
        "soft_bounced": 0,
        "sent": 0,
        "clicked": 1
    ],
]

Answer 1

使用 array_reduce

如您所料，使用array_reduce 可能是您的最佳选择。这有点像一个循环来思考，没有明确使用foreach。这是我的解决方案，我认为这对于您要完成的任务来说非常紧凑。

$result = array_values(array_reduce($source, function($carry, $event) {
    if(!array_key_exists($event['email'], $carry)) {
        $carry[$event['email']] = [
            "first_name" => $event["first_name"],
            "last_name" => $event["last_name"],
            "email" => $event["email"],
            "opened" => 0,
            "blocked" => 0,
            "hard_bounced" => 0,
            "sent" => 0,
            "clicked" => 0
        ];
    }

    $carry[$event['email']][$event["status"]]++;

    return $carry;
}, []));

工作示例：https://3v4l.org/lhlU0

---

使用数组映射

作为练习，我确实尝试了另一种解决方案。它不像array_reduce 那样干净紧凑，但有时至少值得考虑非循环方法。

$result = array_map(function($email) use($source) {
    $events = array_values(array_filter($source, function($event) use($email) {
        return $event['email'] == $email;
    }));


    return [
        "first_name" => $events[0]["first_name"],
        "last_name" => $events[0]["last_name"],
        "email" => $email,
        "opened" => count(array_filter($events, function($event) { return $event["status"] == "opened"; })),
        "blocked" => count(array_filter($events, function($event) { return $event["status"] == "blocked"; })),
        "hard_bounced" => count(array_filter($events, function($event) { return $event["status"] == "hard_bounced"; })),
        "soft_bounced" => count(array_filter($events, function($event) { return $event["status"] == "soft_bounced"; })),
        "sent" => count(array_filter($events, function($event) { return $event["status"] == "sent"; })),
        "clicked" => count(array_filter($events, function($event) { return $event["status"] == "clicked"; })),
    ];
}, array_unique(array_column($source, "email")));

工作示例：https://3v4l.org/KSGeX

虽然我认为应该将这些 count(array_filter(... 调用抽象为一个单独的函数：

function countEvents($events, $status) {
    return count(array_filter($events, function($event) use($status) { 
        return $event["status"] == $status; 
    }));
}

所以现在在上面的返回数组中，您可以只使用countEvents($events, "opened")。会让它更清洁。

Answer 2

我真的不明白为什么不想使用foreach，主要代码体是一样的，这样的事情应该可以工作。

我假设数据在一个多维数组中，并且数组的名字是$old_records;

-> 使用 Foreach

$new_records = [];

foreach ($old_records as $old_record) {

    if(!array_key_exists($old_record["email"], $new_records)) {
        $new_records[$old_record["email"]] = [
            "opened"       => 0,
            "blocked"      => 0,
            "hard_bounced" => 0,
            "soft_bounced" => 0,
            "received"     => 0,
            "clicked"      => 0,
            "sent"         => 0,
        ];
    }

    $new_record = &$new_records[$old_record["email"]];

    $new_record["first_name"] = $old_record["first_name"];
    $new_record["last_name"] = $old_record["last_name"];
    $new_record["email"] = $old_record["email"];

    if(!array_key_exists($old_record["status"], $new_record)) {
        $new_record[$old_record["status"]] = 0;
    }

    $new_record[$old_record["status"]]++;
}

-> 使用 array_reduce

function format($carry, $item) {

    if (empty($carry)) {
        $carry = [];
    }

    if ( ! array_key_exists($item[ "email" ], $carry)) {
        $carry[ $item[ "email" ] ] = [
            "opened"       => 0,
            "blocked"      => 0,
            "hard_bounced" => 0,
            "soft_bounced" => 0,
            "received"     => 0,
            "clicked"      => 0,
            "sent"         => 0,
        ];
    }

    $new_record = &$carry[ $item[ "email" ] ];

    $new_record[ "first_name" ] = $item[ "first_name" ];
    $new_record[ "last_name" ]  = $item[ "last_name" ];
    $new_record[ "email" ]      = $item[ "email" ];

    if ( ! array_key_exists($item[ "status" ], $new_record)) {
        $new_record[ $item[ "status" ] ] = 0;
    }

    $new_record[ $item[ "status" ] ] ++;

    return $carry;
}

array_reduce($old_records, "format");

@Note：我使用电子邮件作为键来合并数据并为状态设置一些默认值，因为在示例中您返回 0 并带有某些不存在的状态。

Answer 3

我生成的关键订单略有不同：

<?php
$json =<<<JSON
[
    {
        "mail_id": "29848947",
        "last_name": "Doe",
        "first_name": "Jon",
        "email": "jdoe@gmail.com",
        "status": "opened"
    },
    {
        "mail_id": "340980398",
        "last_name": "Doe",
        "first_name": "Jane",
        "email": "janedoe@gmail.com",
        "status": "sent"
    },
    {
        "mail_id": "877586",
        "last_name": "Dwaye",
        "first_name": "Jhon",
        "email": "Jhondw@yahoo.com",
        "status": "clicked"
    },
    {
        "mail_id": "225253463",
        "last_name": "Doe",
        "first_name": "Jon",
        "email": "jdoe@gmail.com",
        "status": "opened"
    },
    {
        "mail_id": "849849w4",
        "last_name": "Doe",
        "first_name": "Jane",
        "email": "janedoe@gmail.com",
        "status": "sent"
    }
]
JSON;

方法：

$data = json_decode($json, true);

$status_keys = [
    'opened',
    'blocked',
    'hardbouced', 
    'softbounced',
    'sent',
    'clicked'
];

$skel = array_fill_keys($status_keys, 0);

foreach($data as $item) {
    $email  = $item['email'];
    $status = $item['status'];
    unset($item['status'], $item['mail_id']);

    if(!isset($result[$email]))
        $result[$email] = array_merge($item, $skel);

    $result[$email][$status]++;
}
asort($result);
echo json_encode(array_values($result), JSON_PRETTY_PRINT);

输出：

[
    {
        "last_name": "Doe",
        "first_name": "Jane",
        "email": "janedoe@gmail.com",
        "opened": 0,
        "blocked": 0,
        "hardbouced": 0,
        "softbounced": 0,
        "sent": 2,
        "clicked": 0
    },
    {
        "last_name": "Doe",
        "first_name": "Jon",
        "email": "jdoe@gmail.com",
        "opened": 2,
        "blocked": 0,
        "hardbouced": 0,
        "softbounced": 0,
        "sent": 0,
        "clicked": 0
    },
    {
        "last_name": "Dwaye",
        "first_name": "Jhon",
        "email": "Jhondw@yahoo.com",
        "opened": 0,
        "blocked": 0,
        "hardbouced": 0,
        "softbounced": 0,
        "sent": 0,
        "clicked": 1
    }
]