Remove Duplicate value from JSON Object

Question

I have a JSON object

var data = [
{totalTime: 67, phoneNo: "400-234-090"}, 
{totalTime: 301, phoneNo: "701-080-080"}, 
{totalTime: 300, phoneNo: "400-234-090"}
]

I want to remove duplicate object. Please guide. Output should be as below one

var data = [{totalTime: 301, phoneNo: "701-080-080"}]

@Daniel This is not a duplicate of that. OP wants to **remove** all the duplicates from the array, not just keep all the unique ones. — Blue, Aug 02 '18 at 02:24
Example which you have mentioned is not removing duplicate record. It is just removing occurrence. I need unique records. — Andy, Aug 02 '18 at 02:34
@Andy did any of the answers bellow solve your problem? If so you should mark the answer. It helps others etc. — Akrion, Aug 02 '18 at 17:42

score 2 · Answer 1 · answered Aug 02 '18 at 02:26

2

For a solution with low complexity, I'd first make an object that counts the occurences of each phoneNo, and then filter the input by the count of each object's number being 1:

var data = [
  {totalTime: 67, phoneNo: "400-234-090"}, 
  {totalTime: 301, phoneNo: "701-080-080"}, 
  {totalTime: 300, phoneNo: "400-234-090"}
];
const phoneCounts = data.reduce((a, { phoneNo }) => {
  a[phoneNo] = (a[phoneNo] || 0) + 1;
  return a;
}, {});
console.log(
  data.filter(({ phoneNo }) => phoneCounts[phoneNo] === 1)
);

answered Aug 02 '18 at 02:26

CertainPerformance

356,069
52
309
320

1

@Andy When an answer solves your problem, you can consider marking it as Accepted to indicate that the issue is resolved – CertainPerformance Aug 02 '18 at 03:11
@CertainPerformance can you please guide me how to accept the answer – Andy Aug 02 '18 at 07:09
You can see [here](https://stackoverflow.com/help/someone-answers): `click on the check mark beside the answer to toggle it from greyed out to filled in.` – CertainPerformance Aug 02 '18 at 07:15

score 1 · Answer 2 · answered Aug 02 '18 at 02:40

1

You can just use two filters such that, we will only select objects that are just single entry in the array

const data = [
  {totalTime: 67, phoneNo: "400-234-090"}, 
  {totalTime: 301, phoneNo: "701-080-080"}, 
  {totalTime: 300, phoneNo: "400-234-090"}
]

const newData = data.filter(outer => 
  data.filter(inner => 
    outer.phoneNo === inner.phoneNo
  ).length === 1
)

console.log(newData)

answered Aug 02 '18 at 02:40

Prasanna

4,125
18
41

This has `O(N^2)` complexity... not important in small datasets, but probably not preferable regardless – CertainPerformance Aug 02 '18 at 03:11
@CertainPerformance yes O(n^2) indeed. But has less space complexity as well :) – Prasanna Aug 02 '18 at 03:41

score 0 · Answer 3 · answered Aug 02 '18 at 06:37

Another option (1 reduce, 1 filter and spread):

var data = [
{totalTime: 67, phoneNo: "400-234-090"}, 
{totalTime: 301, phoneNo: "701-080-080"}, 
{totalTime: 300, phoneNo: "400-234-090"}
];

console.log(data.reduce((x, { phoneNo }, i, a) => 
  a.filter((y) => 
 y.phoneNo === phoneNo).length > 1 ? x : [...x, a[i]], []))

Remove Duplicate value from JSON Object

3 Answers3