javascript - 如何在数组对象的嵌套数组的条件上使用 While 循环？

Question

我有以下嵌套数组产品:

products: [
    [{
        Variant: {
            variant_id: '1',
            weight: 15
        },
        Product: {
            _id: '1',
            _shop_id: '1'
        },
        quantity: 5,
        totalPrice: 600
    }],
    [{
            Variant: {
                variant_id: '2',
                weight: 20
            },
            Product: {
                _id: '2',
                _shop_id: '2'
            },
            quantity: 4,
            totalPrice: 500
        },
        {
            Variant: {
                variant_id: '5',
                weight: 25
            },
            Product: {
                _id: '3',
                _shop_id: '2'
            },
            quantity: 3,
            totalPrice: 400
        }
    ]
]

我有一个 packages 数组，需要用 package 对象填充。规则:一个包裹内需包含相同_shop_id(明白)的商品，且商品总重量不得超过30kg限制重量。换句话说，如果Variant.weight的总和超过30，我需要添加一个新的包。例如，products数组需要三个包:

// Package 1 - weight: 15kg - shopId: 1
{Variant: {variant_id: '1', weight: 15}, Product: {_id: '1', _shop_id:'1'}, quantity: 5, totalPrice: 600}

// Package 2 - weight: 20kg - shopId: 2
{Variant: {variant_id: '2', weight: 20}, Product: {_id: '2', _shop_id:'2'}, quantity: 4, totalPrice: 500}

// Package 3 - Needs new package because it would be 45kg - weight: 25kg - shopId: 2
{Variant: {variant_id: '5', weight: 25}, Product: {_id: '3', _shop_id:'2'}, quantity: 3, totalPrice: 400}

我只需要知道包装所有产品需要多少个包裹。 package 对象将在包满后添加，如下所示:

export interface Package {
    weight: number;
}

export class CartComponent {

  someMethod() { 
    let packages: Package[] = [];
    let weight = 0;

    products.forEach(prod =>
      {
          while(weight < 30) {
            weight += prod.Variant.weight;
            let package = { weight: weight };
          }
          packages.push(package);
      }
    });
  }

}

我做错了什么？我需要正确循环 products 数组以了解将使用多少个包。

Answer 1

记住，你有一个数组的数组。当您对外部数组调用 forEach 时，您将获得来自单个商店的产品的内部数组。然后你必须以某种方式迭代内部数组。我建议使用 forEach 而不是 while。以下是我在一些简单测试中的工作:

export class CartComponent {

  someMethod() { 
    let packages: Package[] = [];
    let weight = 0;
    let finishPackage = () => {
      packages.push({ weight: weight });
      weight = 0;
    };

    products.forEach(sameShopProducts =>
      {
        sameShopProducts.forEach(prod => {
          if (weight + prod.Variant.weight > 30) {
            finishPackage();
          }
          weight += prod.Variant.weight;
        });
        // Different shops cannot share a package.
        finishPackage();
      });
    return packages;
  }

}