如何在对象数组中组合类似的对象并插入新的 object？

Question

I have an array of objects for a podcast app that looks like this:

[{ 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" } ]

I want to create a function that combines activity times if the dateListened is on the same day. I want it to look something like this:

[{ 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" } ]

My closest attempts have been to use a.map() with a nested.some() but I'm still far off enough that it's not even worth posting my tries. Does anyone have any hints or ideas of what direction to try next? Thank you!

Answer 1

You could reduce the items and map them to a date key, retrieve the values, and then map them to single objects.

You can key on the following:

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);

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Answer 2

You can achieve the result using reduce and only add the timeInSeconds if its year , month , and date is exactly the same/equal.

 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);