从日期数组中获取每周和每月数据的最佳方法是什么？答案

【问题标题】：What is the best way to get weekly and monthly data from an array of dates?从日期数组中获取每周和每月数据的最佳方法是什么？
【发布时间】：2020-03-23 08:08:36
【问题描述】：

我必须在图表中显示注册用户的每日/每周/每月计数。这是我从后端获得的数据。现在我需要根据视图类型循环遍历数组。我有这样的数据：

[
  {
    "date": "2019-10-28",
    "count": 0
  },
  {
    "date": "2019-10-29",
    "count": 4
  },
  {
    "date": "2019-10-30",
    "count": 5
  },
  {
    "date": "2019-10-31",
    "count": 2
  },
  {
    "date": "2019-11-01",
    "count": 0
  },
  {
    "date": "2019-11-02",
    "count": 6
  },
  {
    "date": "2019-11-03",
    "count": 0
  },
  {
    "date": "2019-11-04",
    "count": 0
  },
  {
    "date": "2019-11-05",
    "count": 0
  },
  {
    "date": "2019-11-06",
    "count": 0
  },
  {
    "date": "2019-11-07",
    "count": 0
  },
  {
    "date": "2019-11-08",
    "count": 0
  },
  {
    "date": "2019-11-09",
    "count": 0
  }
]

如果是每周视图类型，那么我需要得到类似这样的结果：

[
  {
    "week": 44,
    "count": 15
  },
  {
    "week": 45,
    "count": 13
  },
  {
    "week": 46,
    "count": 3
  },
  {
    "week": 47,
    "count": 13
  }
]

如果是每月，那么我需要得到类似这样的结果：

[
  {
    "10": 100,
    "count": 15
  },
  {
    "11": 45,
    "count": 13
  },
  {
    "12": 460,
    "count": 3
  }
]

使用图书馆时刻，我可以获得这样的周数：

array.forEach((item, index) => {
   var weeknumber = moment(item.date).week();
   console.log("Week ", weeknumber);
})

我不确定获得所需结果的最佳方式和最佳方法。有什么建议吗？谢谢！

【问题讨论】：

标签： javascript arrays object foreach momentjs

【解决方案1】：

您需要处理数据并准备通用逻辑以将数据转换为正确的格式。

您可以使用groupBy 和forEach 以及reduce 方法来准备数据，如下例所示

演示：https://repl.it/@abhirathore2006/PrepareDataForCharts

const _ = require('lodash');
// use your dataset
let data = [
  {
    "date": "2019-10-28",
    "count": 0
  },
  {
    "date": "2019-10-29",
    "count": 4
  }
];

// prepare data beforehand to save re-calculations
data.forEach(d=>{
  d.dateObj = new Date(d.date)
});

// this method will sum all the counts in given group
function buildData(data, keyName ){
  let result = []; 
  _.forEach(data, (val, key)=>{
    let totalCounts  = val.reduce((acc, curr)=>{
        return acc + curr.count;
    }, 0)
    result.push({[keyName]:key, count:totalCounts})
  })
  return result;
}

// this will group data by given output of date method
function groupAndBuild(data, dateMethod, groupKey) {
  let groupedData = _.groupBy(data, (d)=>{
    return d.dateObj[dateMethod]()
  })
  return buildData(groupedData, groupKey)
}

// use moment-js or other library to get week number
// and replace dateObj with moment object
console.log(groupAndBuild(data,'getMonth','month'))

【讨论】：