sum 求和数组项

计算数组元素和

计算数组中 order_products 下数组元素 price 的和。

$orders = [
  [
    'id' => 1,
    'user_id' => 1,
    'number' => '13908080808',
    'status' => 0,
    'fee' => 10,
    'discount' => 44,
    'order_products' => [
      [
        'order_id' => 1,
        'product_id' => 1,
        'param' => '6寸',
        'price' => 555.0,
        'product' => ['id' => 1, 'name' => '蛋糕名称', 'images' => []],
      ],
      [
        'order_id' => 1,
        'product_id' => 1,
        'param' => '7寸',
        'price' => 333.0,
        'product' => ['id' => 2, 'name' => '蛋糕名称', 'images' => []],
      ],
    ],
  ],
];

使用 foreach 循环

$price = 0;
foreach ($orders as $order) {
  foreach ($order['order_products'] as $order_product) {
    $price += $order_product['price'];
  }
}

dd($price); // 888.0

声明临时变量记录总价格，配合两次循环获得总价并累计。

使用 map、flatten 和 sum

collect($orders)
    ->map(fn($order) => $order['order_products'])
    ->flatten(1)
    ->map(fn($order) => $order['price'])
    ->sum();

使用 flatMap、pluck 和 sum

collect($orders)
    ->flatMap(fn($order) => $order['order_products'])
    ->pluck('price')
    ->sum();

使用 flatMap 和 sum

collect($orders)
    ->flatMap(fn($order) => $order['order_products'])
    ->sum('price');