Question

我有一个数据源如下

[
  {
    "physicalId": 2110,
    "closedDate": "2017-06-25T00:00:00.000Z",
    "allDay": true
  },
  {
    "physicalId": 2111,
    "closedDate": "2017-06-24T00:00:00.000Z",
    "allDay": true
  },
  {
    "physicalId": 2111,
    "closedDate": "2017-06-25T00:00:00.000Z",
    "allDay": true
  },
  {
    "physicalId": 4299,
    "closedDate": "2017-06-24T00:00:00.000Z",
    "allDay": true
  },
  {
    "physicalId": 4299,
    "closedDate": "2017-06-25T00:00:00.000Z",
    "allDay": true
  }
]

我正在使用lodash v4.17.4按以下方式汇总数据：

[
  {
    "Sat Jun 24 2017 00:00:00 GMT+0000": 2,
    "Sun Jun 25 2017 00:00:00 GMT+0000": 3,
  }
]

但是，我希望以

格式返回对象

[
  {
    date: "Sat Jun 24 2017 00:00:00 GMT+0000"
    total: 2
  },
    {
    date: "Sun Jun 25 2017 00:00:00 GMT+0000"
    total: 3
  }
]

我无法在lodash中找到完成此操作的方法。我怎样才能做到这一点？

Answer 1

您可以在_.map之后使用_.countBy：

_.map(_.countBy(source, "closedDate"), (val, key) => ({ date: key, total: val }))

Answer 2

我不确定，但我认为this mapkey function会有所帮助

Answer 3

使用普通的js，以下两个reduce（）会将原始数据转换为所需的格式：

＆＃13;

let d = [{
    "physicalId": 2110,
    "closedDate": "2017-06-25T00:00:00.000Z",
    "allDay": true
  },
  {
    "physicalId": 2111,
    "closedDate": "2017-06-24T00:00:00.000Z",
    "allDay": true
  },
  {
    "physicalId": 2111,
    "closedDate": "2017-06-25T00:00:00.000Z",
    "allDay": true
  },
  {
    "physicalId": 4299,
    "closedDate": "2017-06-24T00:00:00.000Z",
    "allDay": true
  },
  {
    "physicalId": 4299,
    "closedDate": "2017-06-25T00:00:00.000Z",
    "allDay": true
  }
];

let r = [
  ...d.reduce((a, b) => {
    a.set(b.closedDate, a.has(b.closedDate) ? a.get(b.closedDate) + 1 : 1);
    return a;
  }, new Map)
].reduce((a, b) => {
  let [date, total] = [...b];
  return a.concat({date, total});
}, []);

console.log(r);

＆＃13;

Answer 4

我们在这里使用ES6语法，使用.reduce()和.find()数组助手。

我们还使用ES6 spread operator来更改对象中的现有数据。

这是工作示例。

＆＃13;

var data = [
  {
    "physicalId": 2110,
    "closedDate": "2017-06-25T00:00:00.000Z",
    "allDay": true
  },
  {
    "physicalId": 2111,
    "closedDate": "2017-06-24T00:00:00.000Z",
    "allDay": true
  },
  {
    "physicalId": 2111,
    "closedDate": "2017-06-25T00:00:00.000Z",
    "allDay": true
  },
  {
    "physicalId": 4299,
    "closedDate": "2017-06-24T00:00:00.000Z",
    "allDay": true
  },
  {
    "physicalId": 4299,
    "closedDate": "2017-06-25T00:00:00.000Z",
    "allDay": true
  }
]

const newData = data.reduce((previous, current) => {
  
  const recordExists = previous.find(record => record.date === current.closedDate);
  
  if (!recordExists) {
    return previous =  [ ...previous, { date: current.closedDate, total: 1 } ];
  }
  
  recordExists.total += 1;
  
  return [ ...previous, recordExists ];
}, []);

console.log(newData);

＆＃13;

lodash为countBy函数添加键

4 个答案: