php嵌套foreach意外结果

我不太明白发生了什么事。复制以下代码并运行它，您应该可以看到我看到的内容

$stores = array(
        (object)[
            "store_id" => 1,
        ],
        (object)[
            "store_id" => 2,
        ],
        (object)[
            "store_id" => 3,
        ]
    );

    $currentYear = date('Y');
    $monthes = array();
    for($i = 1; $i <= 4; $i++){
        $temp = new stdClass();
        $temp->month = $i;
        $temp->sales = 0;
        array_push($monthes, $temp);
    }
    foreach($stores as $store){
        $store->sales = array(
            "currentYear" => (object)[
                "year" => $currentYear,
                "monthes" => $monthes,
            ],
        );
    }

    foreach($stores as $store){
        foreach($store->sales as $year){
           foreach($year->monthes as $month){
               $month->sales += 1;
           }
        }
    }

    print_r("<pre>"); 
    print_r($stores);
    print_r("</pre>");

但我预计销售额将是1。而不是3。因为它看起来每个月只访问1次，销售的初始值为0。所以0+=1应该是1。看起来好像它自己绕了三圈

---

我不能对我在这里做错的事耿耿于怀

您正在将相同的

$monthes

数组存储到每个

currentYear

对象中。当您指定阵列时，阵列会被复制，但阵列中包含的对象不会被复制；所有这些数组都包含对相同四个对象的引用。因此，当您增加门店1个月1的销售额时，它也会增加门店2个月1、门店3个月1和门店4个月1的销售额

您需要将创建

$monthes

数组的循环放入填充每个存储的循环中

---

您正在将相同的
$monthes
数组存储到每个
currentYear
对象中。当您指定阵列时，阵列会被复制，但阵列中包含的对象不会被复制；所有这些数组都包含对相同四个对象的引用。因此，当您增加门店1个月1的销售额时，它也会增加门店2个月1、门店3个月1和门店4个月1的销售额

您需要将创建
$monthes
数组的循环放入填充每个存储的循环中


   Array
    (
        [0] => stdClass Object
            (
                [store_id] => 1
                [sales] => Array
                    (
                        [currentYear] => stdClass Object
                            (
                                [year] => 2018
                                [monthes] => Array
                                    (
                                        [0] => stdClass Object
                                            (
                                                [month] => 1
                                                [sales] => 3
                                            )

                                        [1] => stdClass Object
                                            (
                                                [month] => 2
                                                [sales] => 3
                                            )

<?php
$stores = array(
    (object)[
        "store_id" => 1,
        ],
    (object)[
        "store_id" => 2,
        ],
    (object)[
        "store_id" => 3,
        ]
    );

$currentYear = date('Y');
foreach($stores as $store){
    $monthes = array();
    for($i = 1; $i <= 4; $i++){
        $temp = new stdClass();
        $temp->month = $i;
        $temp->sales = 0;
        array_push($monthes, $temp);
    }
    $store->sales = array(
        "currentYear" => (object)[
            "year" => $currentYear,
            "monthes" => $monthes,
            ],
        );
}

foreach($stores as $store){
    foreach($store->sales as $year){
        foreach($year->monthes as $month){
            $month->sales += 1;
        }
    }
}

echo "<pre>";
print_r($stores);
echo "</pre>";