React Native中合并对象列表重复项并累加amount求助

我是一名学习React Native的学生，需要合并一个对象列表，按产品名称累加对应的amount值，同时去除重复项。

原始数据 #

[
    {
        "amount": 125,
        "amountUnit": "gr",
        "productID": { "jumboID": [], "name": "Tarwebloem" }
    },
    {
        "amount": 1,
        "amountUnit": "tl",
        "productID": { "jumboID": [], "name": "Zonnebloem olie" }
    },
    {
        "amount": 3,
        "amountUnit": "st",
        "productID": { "jumboID": [], "name": "Eieren" }
    },
    {
        "amount": 1,
        "amountUnit": "tl",
        "productID": { "jumboID": [], "name": "Zonnebloem olie" }
    },
    {
        "amount": 125,
        "amountUnit": "gr",
        "productID": { "jumboID": [], "name": "Tarwebloem" }
    },
    {
        "amount": 3,
        "amountUnit": "st",
        "productID": { "jumboID": [], "name": "Eieren" }
    },
    {
        "amount": 125,
        "amountUnit": "gr",
        "productID": { "jumboID": [], "name": "Tarwebloem" }
    },
    {
        "amount": 1,
        "amountUnit": "tl",
        "productID": { "jumboID": [], "name": "Zonnebloem olie" }
    },
    {
        "amount": 1,
        "amountUnit": "tl",
        "productID": { "jumboID": [], "name": "Zonnebloem olie" }
    },
    {
        "amount": 3,
        "amountUnit": "st",
        "productID": { "jumboID": [], "name": "Eieren" }
    },
    {
        "amount": 125,
        "amountUnit": "gr",
        "productID": { "jumboID": [], "name": "Tarwebloem" }
    }
]

期望结果 #

[
    {
        "amount": 500,
        "amountUnit": "gr",
        "productID": { "jumboID": [], "name": "Tarwebloem" }
    },
    {
        "amount": 4,
        "amountUnit": "tl",
        "productID": { "jumboID": [], "name": "Zonnebloem olie" }
    },
    {
        "amount": 9,
        "amountUnit": "st",
        "productID": { "jumboID": [], "name": "Eieren" }
    }
]

解决方案 #

可以使用JavaScript的reduce方法实现需求，核心逻辑是用产品名称作为唯一标识，累加对应amount值：

const originalList = [/* 上述原始数据数组 */];

const mergedList = Object.values(
  originalList.reduce((acc, item) => {
    const productName = item.productID.name;
    // 若产品已存在，累加amount
    if (acc[productName]) {
      acc[productName].amount += item.amount;
    } else {
      // 不存在则新增项，浅拷贝避免修改原始数据
      acc[productName] = { ...item };
    }
    return acc;
  }, {})
);

// 输出合并后的结果
console.log(mergedList);

逻辑说明 #

1. 用reduce初始化一个空对象作为累加器，遍历原始列表
2. 以产品名称为key，判断累加器中是否存在该产品
3. 存在则累加amount，不存在则将当前项浅拷贝后存入累加器
4. 最后用Object.values()将累加器的value提取为数组，得到合并结果

内容的提问来源于stack exchange，提问作者Murat