terraform/website/docs/configuration/functions/coalescelist.html.md

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---
layout: "functions"
page_title: "coalescelist - Functions - Configuration Language"
sidebar_current: "docs-funcs-collection-coalescelist"
description: |-
The coalescelist function takes any number of list arguments and returns the
first one that isn't empty.
---
# `coalescelist` Function
-> **Note:** This page is about Terraform 0.12 and later. For Terraform 0.11 and
earlier, see
[0.11 Configuration Language: Interpolation Syntax](../../configuration-0-11/interpolation.html).
`coalescelist` takes any number of list arguments and returns the first one
that isn't empty.
## Examples
```
> coalesce(["a", "b"], ["c", "d"])
[
"a",
"b",
]
> coalesce([], ["c", "d"])
[
"c",
"d",
]
```
To perform the `coalesce` operation with a list of lists, use the `...`
symbol to expand the outer list as arguments:
```
> coalesce([[], ["c", "d"]]...)
[
"c",
"d",
]
```
## Related Functions
* [`coalesce`](./coalesce.html) performs a similar operation with string
arguments rather than list arguments.