javascript - 比较对象数组中的日期和时间

Question

我正在尝试比较日期和时间来处理我的数据。我需要通过检查对象内的 updated_at 键来检查哪些是最新数据。

下面我给出了场景。

// below is my data to be manipulat
[{
  "is_latest": "",
  "created_at": "2021-09-21T21:24:05.000Z",
  "updated_at": "2021-09-21T17:53:29.000Z"
}, {
  "is_latest": "",
  "created_at": "2021-09-22T21:24:05.000Z",
  "updated_at": "2021-09-22T17:53:29.000Z"
}, {
  "is_latest": "",
  "created_at": "2021-09-29T21:24:05.000Z",
  "updated_at": "2021-09-29T17:53:29.000Z" // this is the latest data
}]

我正在尝试这样，但是如何在这里使用 moment 来比较最新的。

for (var i = 0; i < data.length; i++) {
  if (data[i].updated_at > data[i + 1].updated_at) {
    data.is_latest = "true"
  }
}

但我没有得到如下预期的结果。

[{
  "is_latest": "false",
  "created_at": "2021-09-21T21:24:05.000Z",
  "updated_at": "2021-09-21T17:53:29.000Z"
}, {
  "is_latest": "false",
  "created_at": "2021-09-22T21:24:05.000Z",
  "updated_at": "2021-09-22T17:53:29.000Z"
}, {
  "is_latest": true,
  "created_at": "2021-09-29T21:24:05.000Z",
  "updated_at": "2021-09-29T17:53:29.000Z"
}]

我如何使用 map() 或 reduce() 来做到这一点？

Answer 1

您应该检查它的 map 并获取最大日期索引。然后将其值设置为 true；

var data = [
{
  "is_latest": "",
  "created_at": "2021-09-21T21:24:05.000Z",
  "updated_at": "2021-09-21T17:53:29.000Z"
},
{
  "is_latest": "",
  "created_at": "2021-09-22T21:24:05.000Z",
  "updated_at": "2021-09-22T17:53:29.000Z"
},
{
  "is_latest": "",
  "created_at": "2021-09-29T21:24:05.000Z",
  "updated_at": "2021-09-29T17:53:29.000Z"
},
{
  "is_latest": "",
  "created_at": "2021-09-30T21:24:05.000Z",
  "updated_at": "2021-09-30T17:53:29.000Z"
}
]
var maxDateIndex = 0;

var newData = data.map((item, index) => {
  if(item.updated_at > data[maxDateIndex].updated_at) 
      maxDateIndex = index;
  item.is_latest = "false";
  return item;
});

newData[maxDateIndex].is_latest = "true";
console.log(newData);