# Splitting and joining an array

**URL:** https://discourse.nodered.org/t/splitting-and-joining-an-array/80674
**Category:** General
**Created:** [20 August 2023 17:54 UTC](https://discourse.nodered.org/t/splitting-and-joining-an-array/80674 "2023-08-20T17:54:57Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![hugo99](https://avatars.discourse-cdn.com/v4/letter/h/a8b319/32.png) [@hugo99](https://discourse.nodered.org/u/hugo99)
#### Post date: [20 August 2023 17:54 UTC](https://discourse.nodered.org/t/splitting-and-joining-an-array/80674/1 "2023-08-20T17:54:57Z")

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Hi

This seems to be an easy one, but I fail 🙂

I am reading a modbus register and get an array back:  
 ![grafik](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/a/d/ad469be975cfbb8d21b5ce3bfa5fcf7d0b8856d0.png)

I am only interested in parts [0], [3] in order to get back a number: 3579  
I was thinking of a split and join node combination  
Splitting is easy, I get 4 messages back:

![grafik](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/d/b/dbaa82228e7cc1d86ca3444ccc63d11c28f6727e.png)

But how can i join/concatenate [0] and [3] in order to get the value 3579 back?

tnx 🙂

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### Author: ![Steve-Mcl](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/steve-mcl/32/4826_2.png) [@Steve-Mcl](https://discourse.nodered.org/u/Steve-Mcl)
#### Post date: [20 August 2023 18:20 UTC](https://discourse.nodered.org/t/splitting-and-joining-an-array/80674/2 "2023-08-20T18:20:51Z")

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> [@hugo99](#):
>
> But how can i join/concatenate [0] and [3] in order to get the value 3579 back?

Are you certain that is what you want? Seems a bit odd!

Anyhow, since your data is already an array, just concatenate the elements of interest in a function of change node.

Function:

```auto
msg.payload = parseInt(msg.payload[0].toString() + msg.payload[3].toString())
return msg

```

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/5/0/502f5d2d2f1ae6c9fa2f04502cd4237c22397117.png)

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### Author: ![hugo99](https://avatars.discourse-cdn.com/v4/letter/h/a8b319/32.png) [@hugo99](https://discourse.nodered.org/u/hugo99)
#### Post date: [20 August 2023 18:39 UTC](https://discourse.nodered.org/t/splitting-and-joining-an-array/80674/3 "2023-08-20T18:39:03Z")

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> [@Steve-Mcl](#):
>
> ```auto
> msg.payload = parseInt(msg.payload[0].toString() + msg.payload[3].toString())
> return msg
> 
> ```

thank you, this does the job!  
Yes, the values of 0 at position [1] and [2] are strange indeed, but this is what i get back...

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### Author: ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)
#### Post date: [19 October 2023 18:39 UTC](https://discourse.nodered.org/t/splitting-and-joining-an-array/80674/4 "2023-10-19T18:39:28Z")

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