如何在对象数组中组合相似的对象并插入新对象？

Question

我有一个用于播客应用程序的对象数组，如下所示：

[{ id: "uuid-1"
   timeInSeconds: 1000
   dateListened: "2021-01-01T15:57:17.000Z" }, // <---same day
{  id: "uuid-2"
   timeInSeconds: 4900
   dateListened: "2021-01-01T16:57:17.000Z" }, // <---same day 
{  id: "uuid-3"
   timeInSeconds: 3200
   dateListened: "2021-09-01T16:57:17.000Z" }, 
{  id: "uuid-4"
   timeInSeconds: 6000
   dateListened: "2021-10-01T16:57:17.000Z" } ]

如果dateListened在同一天，我想要创建一个结合活动时间的函数。我想让它看起来像这样：

[{ id: "uuid-new" 
   timeInSeconds: 5900 // <---- combined seconds listened on Jan 1
   dateListened: "2021-01-01T15:57:17.000Z" },
{  id: "uuid-3"
   timeInSeconds: 3200
   dateListened: "2021-09-01T16:57:17.000Z" }, 
{  id: "uuid-4"
   timeInSeconds: 6000
   dateListened: "2021-10-01T16:57:17.000Z" } ]

我最近的尝试是使用嵌套的.map()和嵌套的.some()，但我仍然远远不够，甚至不值得发布我的尝试。有没有人对下一步要尝试的方向有任何提示或想法？谢谢!

Answer 1

您可以减少项目并将它们映射到日期键，检索值，然后将它们映射到单个对象。

您可以键入以下内容：

let date = new Date(info.dateListened).toLocaleDateString('en-US')

​

const data = [
  { id: "uuid-1",
    timeInSeconds: 1000,
    dateListened: "2021-01-01T15:57:17.000Z" }, // <---same day
  { id: "uuid-2",
    timeInSeconds: 4900,
    dateListened: "2021-01-01T16:57:17.000Z" }, // <---same day 
  { id: "uuid-3",
    timeInSeconds: 3200,
    dateListened: "2021-09-01T16:57:17.000Z" }, 
  { id: "uuid-4",
    timeInSeconds: 6000,
    dateListened: "2021-10-01T16:57:17.000Z" }
 ];

const result = Object
  .values(data.reduce((acc, info) =>
    (date =>
      ({ ...acc, [date]: [...(acc[date] || []), info ] }))
    (new Date(info.dateListened).toLocaleDateString('en-US')), {}))
  .map(value => value.length === 1 ? value : {
    id: 'uuid-new',
    timeInSeconds: value.reduce((sum, { timeInSeconds }) => sum + timeInSeconds, 0),
    dateListened: value[0].dateListened
  });

console.log(result);

.as-console-wrapper { top: 0; max-height: 100% !important; }

​

Answer 2

您可以使用reduce实现结果，并且只有在其year、month和date完全相同/相等的情况下才能添加timeInSeconds。

​

const arr = [
  {
    id: "uuid-1",
    timeInSeconds: 1000,
    dateListened: "2021-01-01T15:57:17.000Z",
  },
  {
    id: "uuid-2",
    timeInSeconds: 4900,
    dateListened: "2021-01-01T16:57:17.000Z",
  },
  {
    id: "uuid-3",
    timeInSeconds: 3200,
    dateListened: "2021-09-01T16:57:17.000Z",
  },
  {
    id: "uuid-4",
    timeInSeconds: 6000,
    dateListened: "2021-10-01T16:57:17.000Z",
  },
];

const result = arr.reduce((acc, curr) => {
  const { id, timeInSeconds, dateListened } = curr;
  const searchSameDateElement = acc.find((o) => {
    const first = new Date(o.dateListened);
    const second = new Date(dateListened);
    const isYearSame = first.getFullYear() === second.getFullYear();
    const isMonthSame = first.getMonth() === second.getMonth();
    const isDateSame = first.getDate() === second.getDate();
    return isYearSame && isMonthSame && isDateSame;
  });
  if (!searchSameDateElement) {
    acc.push(curr);
  } else {
    searchSameDateElement.timeInSeconds += timeInSeconds;
  }
  return acc;
}, []);

console.log(result);

​