javascript - 如何将以下数组数据分组到上述结构？

Question

目前我有一个数组数据结构，如下面的“实际”下所述。想要以某种方式对其进行分组以获得所需的结构，如下面的“预期”中所述。

我尝试使用 lodash groupBy 、 mapToValues 和 map 将其排列在我想要的结构中，但无法实现。

实际的：

const candyDataSoldByEachDayInYear2000 = [
  {
    candyName: 'snickers',
    data: [{
      date: "2000-01-01", sold: 100
    }, {
      date: "2000-01-02", sold: 110
    }]
  }, {
    candyName: 'kitkat',
    data: [{
      date: "2000-01-01", sold: 80
    }, {
      date: "2000-01-02", sold: 70
    }]
  }, {
    candyName: 'twix',
    data: [{
      date: "2000-01-01", sold: 60
    }, {
      date: "2000-01-02", sold: 50
    }]
  }, {
    candyName: 'milkyway',
    data: [{
      date: "2000-01-01", sold: 60
    }, {
      date: "2000-01-02", sold: 70
    }]
  }, {
    candyName: 'skittles',
    data: [{
      date: "2000-01-01", sold: 120
    }, {
      date: "2000-01-02", sold: 110
    }]
  }];

预期的：

const candyDataSoldByEachDayInYear2000 = [
  {
    date: "2000-01-01",
    candySold: {
      snickers: 100,
      kitkat: 80,
      twix: 60,
      milkyway: 60,
      skittles: 120
    }
  },
  {
    date: "2000-01-02",
    candySold: {
      snickers: 110,
      kitkat: 70,
      twix: 50,
      milkyway: 70,
      skittles: 110
    }
  }
];

.

标签： javascriptarraysperformanceecmascript-6

Answer 1

您可以使用Array.reduce()withArray.forEach()创建一个带有日期键的对象，将糖果添加到相关日期，然后转换为数组Array.values()：

const candyDataSoldByEachDayInYear2000 = [{"candyName":"snickers","data":[{"date":"2000-01-01","sold":100},{"date":"2000-01-02","sold":110}]},{"candyName":"kitkat","data":[{"date":"2000-01-01","sold":80},{"date":"2000-01-02","sold":70}]},{"candyName":"twix","data":[{"date":"2000-01-01","sold":60},{"date":"2000-01-02","sold":50}]},{"candyName":"milkyway","data":[{"date":"2000-01-01","sold":60},{"date":"2000-01-02","sold":70}]},{"candyName":"skittles","data":[{"date":"2000-01-01","sold":120},{"date":"2000-01-02","sold":110}]}];
  
const result = Object.values(candyDataSoldByEachDayInYear2000.reduce((r, { candyName, data }) => {
  data.forEach(({ date, sold }) => {
    if(!r[date]) r[date] = { date, candySold: {} };
    
    const cs = r[date].candySold;
    
    cs[candyName] = (cs[candyName] || 0) + sold;
  });

  return r;
}, {}));

console.log(result);