JavaScript - 按日期对对象数组或记录中的项目进行分组

Question

我需要帮助来显示按日期分组的数组项。我有以下几项数组，每个项都有“今天”字段。

var originalArray = [
        {title: "New Three 123", status: "pending", isDone: false, today: "2018-02-20T16:40:17.759Z", _id: "Eyt44n1svxIjOn5Y"},
        {title: "My First card", status: "pending", isDone: false, today: "2018-02-21T13:00:13.979Z", _id: "UlSoOrLBjX2RldgQ"},
        {title: "Sun Pharma", status: "completed", isDone: true, today: "2018-02-20T16:41:19.040Z", _id: "VbBEyndCIhPDB1Uf"},
        {title: "Design News", status: "pending", isDone: false, today: "2018-02-21T13:00:07.730Z", _id: "rpW4bVIYWjlPMgk6"},
        {title: "Amul India sddsd", status: "pending", isDone: false, today: "2018-02-20T16:41:13.087Z", _id: "uyISWNb7vapmRrNG"}
        ]

要求的输出是需要按日期分组的记录，写在数组项的“今天”键字段中:

    var outputRequired = {
    '2018,2,20' : [
        {title: "New Three 123", status: "pending", isDone: false, today: "2018-02-20T16:40:17.759Z", _id: "Eyt44n1svxIjOn5Y"},     
        {title: "Sun Pharma", status: "completed", isDone: true, today: "2018-02-20T16:41:19.040Z", _id: "VbBEyndCIhPDB1Uf"},       
        {title: "Amul India sddsd", status: "pending", isDone: false, today: "2018-02-20T16:41:13.087Z", _id: "uyISWNb7vapmRrNG"}
    ],
    '2018,2,21' : [
        {title: "My First card", status: "pending", isDone: false, today: "2018-02-21T13:00:13.979Z", _id: "UlSoOrLBjX2RldgQ"},
        {title: "Design News", status: "pending", isDone: false, today: "2018-02-21T13:00:07.730Z", _id: "rpW4bVIYWjlPMgk6"}
    ]
}

请指导我如何实现此输出。

谢谢， 吉涅什·拉瓦尔

Answer 1

您可以使用.reduce 来获得想要的结果。将 initialValue 设置为 {} 并在每次迭代中检查日期键是否存在。如果它存在附加到数组，否则在累加器中创建一个新数组。

var data = originalArray.reduce(
  (acc, el)=>{
    var today = el.today.split("T")[0].replace(/-/g, ",");
    if(acc.hasOwnProperty(today)) acc[today].push(el);
    else acc[today] = [el];
    return acc;
  }, {}
)

在这里查看工作代码:

var originalArray = [{
    title: "New Three 123",
    status: "pending",
    isDone: false,
    today: "2018-02-20T16:40:17.759Z",
    _id: "Eyt44n1svxIjOn5Y"
  },
  {
    title: "My First card",
    status: "pending",
    isDone: false,
    today: "2018-02-21T13:00:13.979Z",
    _id: "UlSoOrLBjX2RldgQ"
  },
  {
    title: "Sun Pharma",
    status: "completed",
    isDone: true,
    today: "2018-02-20T16:41:19.040Z",
    _id: "VbBEyndCIhPDB1Uf"
  },
  {
    title: "Design News",
    status: "pending",
    isDone: false,
    today: "2018-02-21T13:00:07.730Z",
    _id: "rpW4bVIYWjlPMgk6"
  },
  {
    title: "Amul India sddsd",
    status: "pending",
    isDone: false,
    today: "2018-02-20T16:41:13.087Z",
    _id: "uyISWNb7vapmRrNG"
  }
];

var data = originalArray.reduce(
  (acc, el)=>{
    var today = el.today.split("T")[0].replace(/-/g, ",");
    if(acc.hasOwnProperty(today)) acc[today].push(el);
    else acc[today] = [el];
    return acc;
  }, {}
)

console.log(data);