按多个属性对对象进行分组并合并数组属性 [英] Group objects by multiple properties and merge array property

问题描述

在示例中，我使用Each遍历选择字段并创建数据数组，我需要对2个属性year和cabin进行分组，并且属性months是我想要合并的数组，问题是我在获取所需结果时遇到了一些问题：

JSFIDDLE：http://jsfiddle.net/tc39xu6b/2/

我得到的结果：

[
  {
    "year": "2021",
    "cabin": "1",
    "months": [
      "1",
      "2"
    ]
  },
  {
    "year": "2021",
    "cabin": "1",
    "months": [
      "4"
    ]
  },
  {
    "year": "2021",
    "cabin": "2",
    "months": [
      "1",
      "2"
    ]
  },
  {
    "year": "2022",
    "cabin": "1",
    "months": [
      "1",
      "2"
    ]
  },
  {
    "year": "2022",
    "cabin": "1",
    "months": [
      "4"
    ]
  },
  {
    "year": "2022",
    "cabin": "2",
    "months": [
      "1",
      "2"
    ]
  }
]

这就是我需要的结果：

{
  "2021": [
      {"cabin":1, "months": ["1", "2","4"]},
      {"cabin":2, "months": ["1", "2"]}
  ],
  "2022": [
      {"cabin":1, "months": ["1", "2","4"]},
      {"cabin":2, "months": ["1", "2"]}
  ]
}

推荐答案

这是相当正常的group by情况。下面的代码片段使用reduce()重构您的数组，但您可以直接将逻辑按原样放入函数中：http://jsfiddle.net/83st9wgh/

数据-lang="js"数据-隐藏="假"数据-控制台="真"数据-巴贝尔="假">

const input = [{ "year": "2021", "cabin": "1", "months": ["1", "2"] }, { "year": "2021", "cabin": "1", "months": ["4"] }, { "year": "2021", "cabin": "2", "months": ["1", "2"] }, { "year": "2022", "cabin": "1", "months": ["1", "2"] }, { "year": "2022", "cabin": "1", "months": ["4"] }, { "year": "2022", "cabin": "2", "months": ["1", "2"] }];

const result = input.reduce((acc, { year, cabin, months }) => {
  const yearArray = (acc[year] ??= []);

  let cIndex = yearArray.findIndex(o => o.cabin === cabin);
  if (cIndex === -1) {
    cIndex = yearArray.push({ cabin, months: [] }) - 1;
  }

  const monthsArray = yearArray[cIndex].months;
  yearArray[cIndex].months = [...new Set(monthsArray.concat(months))];

  return acc;
}, {});

console.log(JSON.stringify(result, null, 2));

这篇关于按多个属性对对象进行分组并合并数组属性的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！