CODEWITHSUNDEEP
javascriptarraysreactjsobjectiteration
Jose Peres
Jose Peres

Reputation: 317

How to filter a new object depending of Creation Date?

I have the following object:

[
    { createdAt: "08-08-2020, 12:04:19 am", id: "1" },
    { createdAt: "08-08-2020, 12:04:19 am", id: "2" },
    { createdAt: "08-10-2020, 12:04:19 am", id: "3" },
    { createdAt: "08-10-2020, 12:04:19 am", id: "4" },
    { createdAt: "08-12-2020, 12:04:19 am", id: "5" },
    { createdAt: "08-20-2020, 12:04:19 am", id: "6" }
]

As you can see, every array has a creation date and an specific value. What I wanna do here is to create a new object that looks like this:

[
    { createdAt: "08-08-2020", ids: ["1", "2"] },
    { createdAt: "08-10-2020", ids: ["3", "4"] },
    { createdAt: "08-12-2020", ids: ["5"] },
    { createdAt: "08-20-2020", ids: ["6" ]}
]

Basically arranging the ids by date of creation. I've been trying to filter and map this with ECMA6 but the logic it's just not clear to me.

Any help would be greatly appreciated.

Thanks in advance!

Upvotes: 0

Views: 166

Answers (2)

Unmitigated
Unmitigated

Reputation: 89264

This can be accomplished with a basic reduce operation, grouping elements with the same date using an object.

const arr = [
    { createdAt: "08-08-2020, 12:04:19 am", id: "1" },
    { createdAt: "08-08-2020, 12:04:19 am", id: "2" },
    { createdAt: "08-10-2020, 12:04:19 am", id: "3" },
    { createdAt: "08-10-2020, 12:04:19 am", id: "4" },
    { createdAt: "08-12-2020, 12:04:19 am", id: "5" },
    { createdAt: "08-20-2020, 12:04:19 am", id: "6" }
];
const res = Object.values(
  arr.reduce((acc,{createdAt, id})=>{
    const date = createdAt.split(",")[0];
    acc[date] = acc[date] || {createdAt: date, ids: []};
    acc[date].ids.push(id);
    return acc;
  }, {})
);
console.log(res);

Upvotes: 0

gbalduzzi
gbalduzzi

Reputation: 10176

First, create a map between the createdAt and the ids

const array = [
    { createdAt: "08-08-2020, 12:04:19 am", id: "1" },
    { createdAt: "08-08-2020, 12:04:19 am", id: "2" },
    { createdAt: "08-10-2020, 12:04:19 am", id: "3" },
    { createdAt: "08-10-2020, 12:04:19 am", id: "4" },
    { createdAt: "08-12-2020, 12:04:19 am", id: "5" },
    { createdAt: "08-20-2020, 12:04:19 am", id: "6" }
]

const map = {}

array.forEach(item => {
  if (map[item.createdAt] === undefined) {
    map[item.createdAt] = []
  }

  map[item.createdAt].push(item.id)
})

Then, rearrange the map into an array:

const resultingArray = Object.entries(map).map(([createdAt, ids]) => ({
  createdAt,
  ids
}))

Upvotes: 1

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