---
title: array.concat() function
description: >
  `array.concat()` appends two arrays and returns a new array.
menu:
  flux_v0_ref:
    name: array.concat
    parent: array
    identifier: array/concat
weight: 101

introduced: 0.173.0
---

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`array.concat()` appends two arrays and returns a new array.



Neither input array is mutated and a new array is returned.

##### Function type signature

```js
(<-arr: [A], v: [A]) => [A]
```

{{% caption %}}
For more information, see [Function type signatures](/flux/v0/function-type-signatures/).
{{% /caption %}}

## Parameters

### arr

First array. Default is the piped-forward array (`<-`).



### v
({{< req >}})
Array to append to the first array.




## Examples

### Merge two arrays

```js
import "array"

a = [1, 2, 3]
b = [4, 5, 6]

c = a |> array.concat(v: b)

// Returns [1, 2, 3, 4, 5, 6]
// Output each value in the array as a row in a table
array.from(rows: c |> array.map(fn: (x) => ({_value: x})))

```

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{{% expand "View example output" %}}

#### Output data

| _value  |
| ------- |
| 1       |
| 2       |
| 3       |
| 4       |
| 5       |
| 6       |

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