通过在javascript中保存数据(将数组中的值推入)来减少相同键值的对象数组？

Question

我有以下格式的数据，基本上是一个对象数组，我已经尝试了几种方法，我如何才能更有效地做到这一点？

const overdue =  [
        {
            "user.employeeId": "10001440",
            "objectives": [
                "Understand the financial indexes."
            ]
        },
        {
            "user.employeeId": "10000303",
            "objectives": [
                "Document preparation & writing skills"
            ]
        },
        {
            "user.employeeId": "10002168",
            "objectives": [
                "Chia ratio setting for Fuze Tea products L11"
            ]
        },

        {
            "user.employeeId": "10002168",
            "objectives": [
                "Brix parameter differences between Processing and Production of Fuze Tea Lemon-Lemongrass standardization"
            ]
        },
        {
            "user.employeeId": "10002168",
            "objectives": [
                "Paramix Line 9 setting parameter standardization"
            ]
        },
    ]

如何使用lodash通过JavaScript将其转换为以下内容？？

[
        {
            "user.employeeId": "10001440",
            "objectives": [
                "Understand the financial indexs."
            ]
        },
        {
            "user.employeeId": "10000303",
            "objectives": [
                "Document preparation & writing skills"
            ]
        },
        {
            "user.employeeId": "10002168",
            "objectives": [
                "Brix parameter differences between Processing and Production of Fuze Tea Lemon-Lemongrass standardization",
                "Paramix Line 9 setting parameter standardization",
                "Chia ratio setting for Fuze Tea products L11"
            ]
        }
    ]

我已经尝试过Array.map了！和正常的逻辑，我们如何使用lodash reduce或arr.reduce更有效地做到这一点呢？

Answer 1

您可以使用Array.reduce来实现所需的结果，将数组用作累加器。

我们枚举过期数组中的每个对象，如果它不存在于输出数组中，我们添加它，否则我们将对象目标添加到输出中的相关元素。

​

const overdue =  [ { "user.employeeId": "10001440", "objectives": [ "Understand the financial indexes." ] }, { "user.employeeId": "10000303", "objectives": [ "Document preparation & writing skills" ] }, { "user.employeeId": "10002168", "objectives": [ "Chia ratio setting for Fuze Tea products L11" ] }, { "user.employeeId": "10002168", "objectives": [ "Brix parameter differences between Processing and Production of Fuze Tea Lemon-Lemongrass standardization" ] }, { "user.employeeId": "10002168", "objectives": [ "Paramix Line 9 setting parameter standardization" ] }, ]; 

let result = overdue.reduce((res, row) => {
    let el = res.find(el => el["user.employeeId"] === row["user.employeeId"]);
    // If we find the object in the output array simply update the objectives
    if (el) {
       el.objectives = [...el.objectives, ...row.objectives];
    } else {
    // If we _don't_ find the object, add to the output array.
      res.push({ ...row});
    }
    return res;
}, [])

console.log("Result:",result);

​

Answer 2

使用array.reduce并将对象传递给累加器。在回调函数中，检查累加器是否有与user.employeeId的值相同的键。如果不是，则创建键并将迭代下的当前对象添加为它的值。如果已经有一个键，那么只需更新objectives数组即可。当检索值为Object.value时，它将给出一个数组

​

const overdue = [{
    "user.employeeId": "10001440",
    "objectives": [
      "Understand the financial indexes."
    ]
  },
  {
    "user.employeeId": "10000303",
    "objectives": [
      "Document preparation & writing skills"
    ]
  },
  {
    "user.employeeId": "10002168",
    "objectives": [
      "Chia ratio setting for Fuze Tea products L11"
    ]
  },

  {
    "user.employeeId": "10002168",
    "objectives": [
      "Brix parameter differences between Processing and Production of Fuze Tea Lemon-Lemongrass standardization"
    ]
  },
  {
    "user.employeeId": "10002168",
    "objectives": [
      "Paramix Line 9 setting parameter standardization"
    ]
  },
];



let newData = overdue.reduce((acc, curr) => {
  if (!acc[curr['user.employeeId']]) {
    acc[curr['user.employeeId']] = curr;
  } else {
    curr.objectives.forEach((item) => {
      acc[curr['user.employeeId']]['objectives'].push(item)
    })
  }
  return acc;
}, {});


console.log(Object.values(newData))

​

Answer 3

我不确定如何在lodash中做到这一点，但下面是我只使用普通Javascript就能做到的方法：

​

const overdue = [{
    "user.employeeId": "10001440",
    "objectives": [
      "Understand the financial indexes."
    ]
  },
  {
    "user.employeeId": "10000303",
    "objectives": [
      "Document preparation & writing skills"
    ]
  },
  {
    "user.employeeId": "10002168",
    "objectives": [
      "Chia ratio setting for Fuze Tea products L11"
    ]
  },

  {
    "user.employeeId": "10002168",
    "objectives": [
      "Brix parameter differences between Processing and Production of Fuze Tea Lemon-Lemongrass standardization"
    ]
  },
  {
    "user.employeeId": "10002168",
    "objectives": [
      "Paramix Line 9 setting parameter standardization"
    ]
  },
];

const combined = {};

overdue.forEach(o => {
  const id = o["user.employeeId"];
  const obj = o["objectives"][0];
  
  if(!combined[id]) { combined[id] = [obj]; }
  else { combined[id].push(obj); }
  
});

const result = [];

Object.keys(combined).forEach(key => {
  result.push({"user.employeeId" : key, "objectives" : combined[key]});
});

console.log(result);

​