How to remove duplicate sub object array from JS array?

Question

I have a js object array as below

[
[
 {file: 'file1',
  status: 'pending',
  time: '2021-08-13 11:20:00'
 },
 {file: 'file2',
  status: 'pending',
  time: '2021-08-13 11:20:00'
 }
],
[
 {file: 'file1',
  status: 'completed',
  time: '2021-08-13 09:30:00'
 },
 {file: 'file2',
  status: 'completed',
  time: '2021-08-13 09:30:00'
 }
],
[
 {file: 'file3',
  status: 'completed',
  time: '2021-08-14 06:50:00'
 }
]
]

And i need to filter the array based on the file field and remove the duplicated sub arrays. So the output should look like

[
[
 {file: 'file1',
  status: 'pending',
  time: '2021-08-13 11:20:00'
 },
 {file: 'file2',
  status: 'pending',
  time: '2021-08-13 11:20:00'
 }
],
[
 {file: 'file3',
  status: 'completed',
  time: '2021-08-14 06:50:00'
 }
]
]

What is the easiest way to do this. Can we use ES6 here?

"Can we use ES6 here" Well that's up to you. Otherwise, if I correctly guess your usecase, why not use an object with the file name (or hash to avoid duplicates) as keys ? — Seblor
– Seblor, Commented Aug 13, 2021 at 19:00

Nitheesh · Accepted Answer · 2021-08-15 03:57:19Z

2

Try using Array.reduce.

Please see the code comments for logic.

const input = [
    [
        { file: 'file1', status: 'pending', time: '2021-08-13 11:20:00' },
        { file: 'file2', status: 'pending', time: '2021-08-13 11:20:00' }
    ],
    [
        { file: 'file1', status: 'completed', time: '2021-08-13 09:30:00' },
        { file: 'file2', status: 'completed', time: '2021-08-13 09:30:00' }
    ],
    [
        { file: 'file3', status: 'completed', time: '2021-08-14 06:50:00' }
    ]
]
const output = input.reduce((acc, curr) => {
    let isNodeExist = false;
    /*
     * Each node of the accumulator acc will be an array
     * Which means the accumulator acc is an array of arrays
     * The current node curr will also be an array
     * So we have to verify the array curr has the same set present
     * For that there should be a child node present in acc with the same length of curr
     * Also the each name of curr should be there in that matching node
     */
    acc.forEach((node) => {
        isNodeExist = node.length === curr.length;
        if (isNodeExist) {
            curr.forEach((currNode) => {
                isNodeExist = isNodeExist && (node.find((item) => item.file === currNode.file) !== undefined);
            })
        }
    });
    if(!isNodeExist) {
        acc.push(curr);
    }
    return acc;
}, []);
console.log(output);

edited Aug 15, 2021 at 3:57

answered Aug 14, 2021 at 16:15

Nitheesh

20.1k3 gold badges28 silver badges52 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

vsemozhebuty Over a year ago

It seems there is one more condition to be considered. See comments to my answer for details.

Nitheesh Over a year ago

@vsemozhebuty hmm. The logic for filtering is not correctly mentioned in the question. Any way I have updated my answer, just to make sure that not to post an incorrect solution.

vsemozhebuty · Accepted Answer · 2021-08-14 16:14:17Z

1

If you need to save just the first instance with the same group of names, this is a possible way:

const data = [
  [
    {file: 'file1',
      status: 'pending',
      time: '2021-08-13 11:20:00'
    },
    {file: 'file2',
      status: 'pending',
      time: '2021-08-13 11:20:00'
    }
  ],
  [
    {file: 'file1',
      status: 'completed',
      time: '2021-08-13 09:30:00'
    },
    {file: 'file2',
      status: 'completed',
      time: '2021-08-13 09:30:00'
    }
  ],
  [
    {file: 'file3',
      status: 'completed',
      time: '2021-08-14 06:50:00'
    }
  ],
  [
    {file: 'file2',
      status: 'completed',
      time: '2021-08-14 06:50:00'
    }
  ],
];

const filteredData = [];
const seenFiles = new Set();

for (const group of data) {
  const fileNames = JSON.stringify(group.map(({ file }) => file).sort());

  if (!seenFiles.has(fileNames)) {
    seenFiles.add(fileNames);
    filteredData.push(group);
  }
}

console.log(filteredData);

edited Aug 14, 2021 at 16:14

answered Aug 14, 2021 at 15:22

vsemozhebuty

13.9k1 gold badge29 silver badges28 bronze badges

6 Comments

ahkam Over a year ago

Appreciate ur answer. Here, if you change last object name from file3 -> file2 , it's eliminating too. But I need to consider them as separate. If there are sub arrays within the parent array, and they are subset within themselves, they should be separate

vsemozhebuty Over a year ago

@ahkam What do you mean by "subset within themselves"? It seems you have just 3 levels: main array — group subarrays — files.

ahkam Over a year ago

group subarrays may have objects with same file. So i want to consider them as 2 different group subarrays

vsemozhebuty Over a year ago

@ahkam Sorry, I still do not understand what distinguishes the object with file2 from the second subarray and the object with possible file2 from the third subarray. Why the former is considered duplicate and the latter is not. Maybe you need more explanation in the question...

ahkam Over a year ago

Sorry if the question is not clear enough. If the sub arrays contain same number of objects with same name, it should be considered as duplicates. But if the size of the sub arrays are varying and one sub array is a subset of another, it should be considered as two different. Basically these sub arrays are the requests made by the user. If the sub array are equal in size and the file names are same, user has requested the file set twice. So i need to show it as a single request

|

Collectives™ on Stack Overflow

How to remove duplicate sub object array from JS array?

2 Answers 2

2 Comments

6 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

6 Comments

Your Answer

Sign up or log in

Post as a guest

Related