# Remove duplicates from an array of objects
**URL:** https://discourse.nodered.org/t/remove-duplicates-from-an-array-of-objects/28013
**Category:** General
**Created:** [8 June 2020 21:07 UTC](https://discourse.nodered.org/t/remove-duplicates-from-an-array-of-objects/28013 "2020-06-08T21:07:26Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Paul-Reed](https://discourse.nodered.org/u/Paul-Reed)
#### Post date: [8 June 2020 21:07 UTC](https://discourse.nodered.org/t/remove-duplicates-from-an-array-of-objects/28013/1 "2020-06-08T21:07:26Z")
> [@Dashboard Charts - 7 day rolling average](https://discourse.nodered.org/t/dashboard-charts-7-day-rolling-average/27145/11):
>
> looking at your original data - why do you have duplicate x values ?
Talk about a self fulfilling prophecy!!
I've noticed that duplicate entries have started to appear in my data feed, which are creating errors in a 7 day rolling average calculation.
So I'm getting now something like;
```auto
[{
"x": 1591315200000,
"y": 8
}, {
"x": 1591315200000,
"y": 8
}, {
"x": 1591315200000,
"y": 8
}, {
"x": 1591228800000,
"y": 30
}]
```
So 3 of the 4 entries are identical, and I need just a unique entry for each timestamp, like;
```auto
[{
"x": 1591315200000,
"y": 8
}, {
"x": 1591228800000,
"y": 30
}]
```
I've googled, and found several solutions, but not really found one that works.
Is there an easy way to filter out the duplicates?
---
### Author:  [@michaelblight](https://discourse.nodered.org/u/michaelblight)
#### Post date: [9 June 2020 04:17 UTC](https://discourse.nodered.org/t/remove-duplicates-from-an-array-of-objects/28013/2 "2020-06-09T04:17:30Z")
I would take the lazy approach and use a function node.
```auto
var prev = null;
msg.payload = msg.payload.filter((item) => {
var keep = (item.x !== prev);
prev = item.x;
return keep;
});
return msg;
```
This assumes you only want to dedupe on 'x', and they are all in sequence. You would have to modify it a bit if that's not the case.
---
### Author:  [@Paul-Reed](https://discourse.nodered.org/u/Paul-Reed)
#### Post date: [9 June 2020 08:37 UTC](https://discourse.nodered.org/t/remove-duplicates-from-an-array-of-objects/28013/3 "2020-06-09T08:37:52Z")
Perfect! thanks Michael.
---
### Author:  [@Paul-Reed](https://discourse.nodered.org/u/Paul-Reed)
#### Post date: [23 June 2020 08:37 UTC](https://discourse.nodered.org/t/remove-duplicates-from-an-array-of-objects/28013/4 "2020-06-23T08:37:55Z")
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