How to find a duplicate object (all key value pair should be same) in an array using ES6 HOF Javascript [duplicate]

Question

var records = [ 
   { 
      "defaultContact":true,
      "contactName":"testContactName",
      "mobileNumber":"900000000000",
      "mobileDialCode":"+91 IN",
      "faxNumber":"123",
      "faxDialCode":"+91 IN",
      "emailId":"[email protected]"
   },
   { 
      "defaultContact":false,
      "contactName":"xyz",
      "mobileNumber":"900000001000",
      "mobileDialCode":"+91 IN",
      "faxNumber":"123",
      "faxDialCode":"+91 IN",
      "emailId":"[email protected]"
   },
   { 
      "defaultContact":false,
      "contactName":"asdasd",
      "mobileNumber":"123",
      "mobileDialCode":"+91 IN",
      "faxNumber":"",
      "faxDialCode":"",
      "emailId":""
   },
   { 
      "contactName":"asdasd",
      "defaultContact":false,
      "emailId":"",
      "faxDialCode":"",
      "faxNumber":"",
      "mobileDialCode":"+91 IN",
      "mobileNumber":"123"
   }
];

The above is an array of object i have done this using two for loops but this doesn't look good, can anyone suggest how to do it with ES6 Higher order functions.

here duplicate means when each & every property matched exactly same.

below is how i did it:

let duplicateRecords = [];
    for (let i = 0; i < records.length; i++) {
      for (let j = i + 1; j < records.length; j++) {
        if (
          records[i].contactName === records[j].contactName &&
          records[i].emailId === records[j].emailId &&
          records[i].faxDialCode === records[j].faxDialCode &&
          records[i].faxNumber === records[j].faxNumber &&
          records[i].mobileDialCode === records[j].mobileDialCode &&
          records[i].mobileNumber === records[j].mobileNumber
        ) {
          duplicateRecords = [records[j]];
        }
      }
    }

Any help would be appreciated.

Thanks @Prabhjot Singh Kainth No, i want the duplicate object if there is any. — Nakul Nagariya
– Nakul Nagariya, Commented Jan 2, 2020 at 11:07
Change duplicateRecords = [records[j]]; to duplicateRecords.push(records[j]);. — Felix Kling
– Felix Kling, Commented Jan 2, 2020 at 11:16
Thanks @FelixKling for the suggestion but i want this to be converted and done by using ES6 functions, anyway the above was working but if you can suggest something could be achieved by using Array.every() or something like that. — Nakul Nagariya
– Nakul Nagariya, Commented Jan 2, 2020 at 11:20
FWIW, Array.every is already part of ES5. every wouldn't make sense in your case since you want to get the duplicate records back. every returns a boolean. — Felix Kling
– Felix Kling, Commented Jan 2, 2020 at 11:32

Aleksandr Kuharenko · Accepted Answer · 2020-01-02 12:07:33Z

1

In your case using loop for is more appropriate than high-order function. But you can use Object.keys and Array.filter to make your code more universal and short.

for (let i = 0; i < records.length; i++) {
   const keys = Object.keys(records[i]);
     for (let j = i + 1; j < records.length; j++) {
         const isDublicated = !Boolean(keys.filter(key => records[i][key] !== records[j][key]).length);
         isDublicated ? dublicatedRecords.push(records[j]) : null;
     }
}

Or using high-order functions:

const dublicatedRecords = records.reduce((acc, record, index) => {
  const keys = Object.keys(record);
  records.forEach((otherRecord, otherIndex) => {
      const isDublicated = !Boolean(keys.filter(key => record[key] !== otherRecord[key]).length);
      isDublicated && index !== otherIndex ? acc.push(otherRecord) : null;
  })
  return acc;
}, []);

edited Jan 2, 2020 at 12:07

answered Jan 2, 2020 at 11:43

Aleksandr Kuharenko

4914 silver badges6 bronze badges

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

2 Comments

Nakul Nagariya Over a year ago

Pretty much same but thanks for adding some ES6 flavor to it, that's what i wanted. do you know anything like can we done in lodash, just this looping doesn't look good.

Aleksandr Kuharenko Over a year ago

updated answer with solution without for

Collectives™ on Stack Overflow

How to find a duplicate object (all key value pair should be same) in an array using ES6 HOF Javascript [duplicate]

1 Answer 1

2 Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Linked

Related