在TypeScript中对键对值数组进行排序

Question

以下是TypeScript中的动态数组，我希望按激活日期降序排序。

notificationList = [];

notificationList = [ {"Id:11", "ActivationDate":"29-Jan-2018"},
{"Id:21", "ActivationDate":"22-Jan-2018"},
{"Id:8", "ActivationDate":"01-Feb-2018"},
{"Id:10", "ActivationDate":"25-Jan-2018"},
{"Id:12", "ActivationDate":"24-Jan-2018"},
{"Id:05", "ActivationDate":"28-Jan-2018"},
{"Id:04", "ActivationDate":"24-Jan-2018"},
]

我正在使用下面的代码进行排序，但它没有给我预期的输出。

this.notificationList = this.notificationList.sort(function(a, b): any {
              const dateA = new Date(a['ActivationDate']);
              const dateB = new Date(b['ActivationDate']);
              console.log('dateA -' + dateA);
              console.log('dateB -' + dateB);
              console.log(dateB > dateA);
              return dateB > dateA; //sort by date decending
          });

有任何建议或意见吗？

Answer 1

要排序的回调应该return a number：

let notificationList = [
    { "Id": 11, "ActivationDate": "29 Jan 2018" },
    { "Id": 21, "ActivationDate": "22 Jan 2018" },
    { "Id": 8, "ActivationDate": "01 Feb 2018" },
    { "Id": 10, "ActivationDate": "25 Jan 2018" },
    { "Id": 12, "ActivationDate": "24 Jan 2018" },
    { "Id": 5, "ActivationDate": "28 Jan 2018" },
    { "Id": 4, "ActivationDate": "24 Jan 2018" },
];

notificationList = notificationList.sort(function (a, b): any {
    const dateA = new Date(a['ActivationDate']);
    const dateB = new Date(b['ActivationDate']);
    return dateB > dateA ? 1 : dateB < dateA ? -1 : 0; //sort by date decending
});

注意您使用的日期格式为not officially supported，仅适用于Chrome。我从日期中删除了-，将日期转换为支持的格式。

Answer 2

您的比较是错误的，您应该使用<代替<

this.notificationList.sort((a, b)=> {
  let dateA = new Date(a['ActivationDate']);
  let dateB =  new Date(b['ActivationDate']);
  return dateA < dateB; // sort by descending
});

<强> LIVE DEMO