javascript 中具有最新日期的過濾數組

Question

我有一個具有相同隊列 ID、stats_type 和 service_date_end 的數組

[
  {
    cohort_id: '1',
    stats_type: 'comprehensive',
    service_date_end: '2020-11-30',
    calculation_time: '2021-01-04 11:20:20'
  },
  {
    cohort_id: '1',
    stats_type: 'comprehensive',
    service_date_end: '2020-11-30',
    calculation_time: '2021-01-04 09:20:20'
  },
  {
    cohort_id: '1',
    stats_type: 'comprehensive',
    service_date_end: '2020-11-30',
    calculation_time: '2021-01-04 09:19:20'
  },
  {
    cohort_id: '1',
    stats_type: 'comprehensive',
    service_date_end: '2020-11-30',
    calculation_time: '2021-01-03 09:19:20'
  },
  {
    cohort_id: '1',
    stats_type: 'comprehensive',
    service_date_end: '2021-01-01',
    calculation_time: '2021-01-01 09:19:20'
  },
  {
    cohort_id: '1',
    stats_type: 'comprehensive',
    service_date_end: '2020-11-30',
    calculation_time: '2021-01-01 09:19:20'
  },
  {
    cohort_id: '1',
    stats_type: 'diagnostic',
    service_date_end: '2020-11-30',
    calculation_time: '2021-01-03 09:19:20'
  },
  {
    cohort_id: '1',
    stats_type: 'diagnostic',
    service_date_end: '2020-11-30',
    calculation_time: '2021-01-02 09:19:20'
  }
]

對於每個相同的統計數據類型和服務日期結束，我只想擁有那些具有最新計算時間的記錄，並從數組中消除其他數據我如何在 JavaScript 中實現這一點？

Answer 1

您可以使用reduce和Object.values過濾它，如下所示：

 const data = [{ cohort_id: '1', stats_type: 'comprehensive', service_date_end: '2020-11-30', calculation_time: '2021-01-04 11:20:20' }, { cohort_id: '1', stats_type: 'comprehensive', service_date_end: '2020-11-30', calculation_time: '2021-01-04 09:20:20' }, { cohort_id: '1', stats_type: 'comprehensive', service_date_end: '2020-11-30', calculation_time: '2021-01-04 09:19:20' }, { cohort_id: '1', stats_type: 'comprehensive', service_date_end: '2020-11-30', calculation_time: '2021-01-03 09:19:20' }, { cohort_id: '1', stats_type: 'comprehensive', service_date_end: '2021-01-01', calculation_time: '2021-01-01 09:19:20' }, { cohort_id: '1', stats_type: 'comprehensive', service_date_end: '2020-11-30', calculation_time: '2021-01-01 09:19:20' }, { cohort_id: '1', stats_type: 'diagnostic', service_date_end: '2020-11-30', calculation_time: '2021-01-03 09:19:20' }, { cohort_id: '1', stats_type: 'diagnostic', service_date_end: '2020-11-30', calculation_time: '2021-01-02 09:19:20' } ] const result = Object.values( data.reduce((res, ele) => { let exist = res[ele.stats_type + ele.service_date_end]??= {...ele} if(exist.calculation_time < ele.calculation_time) exist.calculation_time = ele.calculation_time return res }, {}) ) console.log(result)

用??= 文件

邏輯 nullish assignment (x??= y)運算符僅if x is nullish (null or undefined)分配。