Node.js

Question

在Node.js中，我有3组数据如

[
    {
        "userId":"54c7f3ef-64d4-40de-8100-d2ec81e8aaf3",
        "dailyData":159392.235451,
        "dailyDataInUSC":255.284807
    }
]

和

[
    {
        "userId":"54c7f3ef-64d4-40de-8100-d2ec81e8aaf3",
        "monthlyData":159392.235451,
        "monthlyDataInUSC":255.284807
    }, 
    {
        "userId":"23fs6fds3-34k4-17de-3123-d2ec81e8aaf3",
        "monthlyData":349392.455451,
        "monthlyDataInUSC":655.234807
    }
]

和

[
    {
        "userId":"54c7f3ef-64d4-40de-8100-d2ec81e8aaf3",
        "threeMonthsData":159392.235451,
        "threeMonthsDataInUSC":255.284807
    }, 
    {
        "userId":"23fs6fds3-34k4-17de-3123-d2ec81e8aaf3",
        "threeMonthsData":349392.455451,
        "threeMonthsDataInUSC":655.234807
    }, 
    {
        "userId":"34sdf34-67j4-54nd-6763-d2ec81e8aaf3",
        "threeMonthsData":6789392.455451,
        "threeMonthsDataInUSC":905.655807
    }
]

我如何根据数组中的 userId(filter) 将其合并为一个对象。

例如，输出应该像

[
    {
        "userId":"54c7f3ef-64d4-40de-8100-d2ec81e8aaf3",
        "dailyData":159392.235451,
        "dailyDataInUSC":255.284807,
        "monthlyData":159392.235451,
        "monthlyDataInUSC":255.284807,
        "threeMonthsData":159392.235451,
        "threeMonthsDataInUSC":255.284807
    }
]

请帮我实现这个。

Answer 1

const aa = () => {
  let aa = [
    {
      userId: "54c7f3ef-64d4-40de-8100-d2ec81e8aaf3",
      dailyData: 159392.235451,
      dailyDataInUSC: 255.284807
    }
  ];

  let bb = [
    {
      userId: "54c7f3ef-64d4-40de-8100-d2ec81e8aaf3",
      monthlyData: 159392.235451,
      monthlyDataInUSC: 255.284807
    },
    {
      userId: "23fs6fds3-34k4-17de-3123-d2ec81e8aaf3",
      monthlyData: 349392.455451,
      monthlyDataInUSC: 655.234807
    }
  ];

  let cc = [
    {
      userId: "54c7f3ef-64d4-40de-8100-d2ec81e8aaf3",
      threeMonthsData: 159392.235451,
      threeMonthsDataInUSC: 255.284807
    },
    {
      userId: "23fs6fds3-34k4-17de-3123-d2ec81e8aaf3",
      threeMonthsData: 349392.455451,
      threeMonthsDataInUSC: 655.234807
    },
    {
      userId: "34sdf34-67j4-54nd-6763-d2ec81e8aaf3",
      threeMonthsData: 6789392.455451,
      threeMonthsDataInUSC: 905.655807
    }
  ];

  let newArrObj = aa;
  bb.forEach(item => {
    let index = newArrObj.findIndex(item1 => item1.userId === item.userId);
    if (index === -1) {
      newArrObj = [...newArrObj, item];
    } else {
      newArrObj[index] = { ...newArrObj[index], ...item };
    }
  });
  cc.forEach(item => {
    let index = newArrObj.findIndex(item1 => item1.userId === item.userId);
    if (index === -1) {
      newArrObj = [...newArrObj, item];
    } else {
      newArrObj[index] = { ...newArrObj[index], ...item };
    }
  });
  console.log(newArrObj);
};

Answer 2

spread, reduce and findIndex的组合可以解决问题

使用 spread 运算符将原始数组合并为一个数组。
使用 reduce 按键对元素进行分组（在本例中为 userId）

像这样：

const dailyData = [{"userId":"54c7f3ef-64d4-40de-8100-d2ec81e8aaf3","dailyData":159392.235451,"dailyDataInUSC":255.284807}];
const monthlyData = [{"userId":"54c7f3ef-64d4-40de-8100-d2ec81e8aaf3","monthlyData":159392.235451,"monthlyDataInUSC":255.284807}, {"userId":"23fs6fds3-34k4-17de-3123-d2ec81e8aaf3","monthlyData":349392.455451,"monthlyDataInUSC":655.234807}]
const triMonthlyData = [{"userId":"54c7f3ef-64d4-40de-8100-d2ec81e8aaf3","threeMonthsData":159392.235451,"threeMonthsDataInUSC":255.284807}, {"userId":"23fs6fds3-34k4-17de-3123-d2ec81e8aaf3","threeMonthsData":349392.455451,"threeMonthsDataInUSC":655.234807}, {"userId":"34sdf34-67j4-54nd-6763-d2ec81e8aaf3","threeMonthsData":6789392.455451,"threeMonthsDataInUSC":905.655807}]


const combinedData = [...dailyData, ...monthlyData, ...triMonthlyData].reduce((mergedResult, curElement) => {
  let matchingElementIdx = mergedResult.findIndex(ele => ele.userId === curElement.userId);

  if (matchingElementIdx !== -1) {
    mergedResult[matchingElementIdx] = {...mergedResult[matchingElementIdx], ...curElement};
  } else {
    mergedResult = [...mergedResult, curElement];
  }
  return mergedResult;
}, []);

console.log(combinedData);

Node.js - 如何根据条件合并数组中的对象？

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