How to compare objects of arrays and return unique array in javascript

Question

I have two arrays:

First array:

generalInfo = [{"fName": "Suku", "lName": "Brown", "sex": "Male", "Id": "RY12S"}, {"fName": "Mary", "lName": "Sue", "sex": "Female", "Id": "UT72W"}]

Second array:

paymentInfo = [{"Id": "RY12S", "amount": "1000.00", "purpose": "rent", "date": "2017-17-07"}, {"Id": "UT72W", "amount": "5000.00", "purpose": "renovation", "date": "2017-15-07"}]

Now, I want to be able to compare the Id field for the both arrays and return their unique information.

At least the third should look like this:

specificInfo = [{"Id": "RY12S","fName": "Suku", "lName": "Brown", "amount": "1000.00", "purpose": "rent"}, {"Id": "UT72W","fName": "Mary", "lName": "Sue", "amount": "5000.00", "purpose": "renovation"}]

Is there any easy way to achieve this?

What have you tried? It's expected you at least try, then when/if you have issues, we're happy to help. — StudioTime, Jul 17 '17 at 10:53
Possible duplicate of [Array.push() if does not exist?](https://stackoverflow.com/questions/1988349/array-push-if-does-not-exist) — Atilla Arda Açıkgöz, Jul 17 '17 at 10:54
This is duplicate question. You can check this for your answer: https://stackoverflow.com/questions/1988349/array-push-if-does-not-exist — Atilla Arda Açıkgöz, Jul 17 '17 at 10:54
Possible dublicate : https://stackoverflow.com/questions/18383636/compare-2-arrays-of-objects-with-underscore-to-find-the-differnce — Dave Ranjan, Jul 17 '17 at 10:54

score 0 · Answer 1 · answered Jul 17 '17 at 11:00

An ES6 solution with map and find:

var generalInfo = [{"fName": "Suku", "lName": "Brown", "sex": "Male", "Id": "RY12S"}, {"fName": "Mary", "lName": "Sue", "sex": "Female", "Id": "UT72W"}];

var paymentInfo = [{"Id": "RY12S", "amount": "1000.00", "purpose": "rent", "date": "2017-17-07"}, {"Id": "UT72W", "amount": "5000.00", "purpose": "renovation", "date": "2017-15-07"}];

var uniqueInfo = generalInfo.map((generalItem) => {
  var paymentItem = paymentInfo.find((item) => item.Id === generalItem.Id);

  return {
    Id: generalItem.Id,
    fName: generalItem.fName,
    lName: generalItem.lName,
    amount: paymentItem.amount,
    purpose: paymentItem.purpose
  };
});

console.log(uniqueInfo);

Try to understand the logic behind this and, if you need to implement in ES5, try to do by yourself before posting here.

How to compare objects of arrays and return unique array in javascript

1 Answers1