# Working with arrays
**URL:** https://discourse.nodered.org/t/working-with-arrays/73487
**Category:** General
**Tags:** function-node
**Created:** [10 January 2023 17:30 UTC](https://discourse.nodered.org/t/working-with-arrays/73487 "2023-01-10T17:30:49Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@IngoKnito](https://discourse.nodered.org/u/IngoKnito)
#### Post date: [10 January 2023 17:30 UTC](https://discourse.nodered.org/t/working-with-arrays/73487/1 "2023-01-10T17:30:49Z")
Possible Noob-question 🙂 - yes i have seached in the docu and have found not an answer.
I create a msg with:
```auto
var num = msg.payload;
msg.payload = [{ "Test": parseFloat(num) }];
return msg;
```
Now i want to replace the "test" with a variable.
```auto
var num = msg.payload;
var testindex = "Test"
msg.payload = [{ testindex: parseFloat(num) }];
return msg;
```
But this does not work.
It results in an array with "testindex: 1673371589863" - but not with the variable like "Test: 1673371589863" as expected.
---
### Author:  [@bakman2](https://discourse.nodered.org/u/bakman2)
#### Post date: [10 January 2023 17:50 UTC](https://discourse.nodered.org/t/working-with-arrays/73487/2 "2023-01-10T17:50:07Z")
Is there a reason why it needs to output an array with a single object ?
a dirty way:
```auto
const num = msg.payload;
const property = "test"
msg.payload = [{ [`${property}`]: parseFloat(num) }];
return msg;
```
---
### Author:  [@IngoKnito](https://discourse.nodered.org/u/IngoKnito)
#### Post date: [10 January 2023 18:06 UTC](https://discourse.nodered.org/t/working-with-arrays/73487/3 "2023-01-10T18:06:17Z")
Ahhh. Great! That works well.
Thanks for the quick reply! 🙂
To the question: It is for the elimination of multiple function nodes to only one and to avoid typos 😉
---
### Author:  [@E1cid](https://discourse.nodered.org/u/E1cid)
#### Post date: [10 January 2023 18:27 UTC](https://discourse.nodered.org/t/working-with-arrays/73487/4 "2023-01-10T18:27:43Z")
> [@bakman2](#):
>
> msg.payload = [{ [` ${property}`]: parseFloat(num) }];
Just for info. The string template is not needed
```auto
msg.payload = [{ [property]: parseFloat(num) }];
```
Should be fine.
---
### Author:  [@bakman2](https://discourse.nodered.org/u/bakman2)
#### Post date: [10 January 2023 18:30 UTC](https://discourse.nodered.org/t/working-with-arrays/73487/5 "2023-01-10T18:30:58Z")
> [@E1cid](#):
>
> Just for info. The string template is not needed
Yeah thats what i thought, it didnt work here (initially), must have made a typo.
---
### Author:  [@IngoKnito](https://discourse.nodered.org/u/IngoKnito)
#### Post date: [10 January 2023 18:56 UTC](https://discourse.nodered.org/t/working-with-arrays/73487/6 "2023-01-10T18:56:06Z")
Looks good, but does not work.
The result is "undefined: 1673376899329"
---
### Author:  [@E1cid](https://discourse.nodered.org/u/E1cid)
#### Post date: [10 January 2023 19:05 UTC](https://discourse.nodered.org/t/working-with-arrays/73487/7 "2023-01-10T19:05:25Z")
You have some sort of typo or a undefined variable `property`.
As working perfectly fine here
---
### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [11 March 2023 19:05 UTC](https://discourse.nodered.org/t/working-with-arrays/73487/8 "2023-03-11T19:05:51Z")
This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.