terraform/website/docs/language/functions/concat.mdx

---
page_title: concat - Functions - Configuration Language
description: The concat function combines two or more lists into a single list.
---

⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️
> [!IMPORTANT]  
> **Documentation Update:** Product documentation previously located in `/website` has moved to the [`hashicorp/web-unified-docs`](https://github.com/hashicorp/web-unified-docs) repository, where all product documentation is now centralized. Please make contributions directly to `web-unified-docs`, since changes to `/website` in this repository will not appear on developer.hashicorp.com.
⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️⚠️


# `concat` Function

`concat` takes two or more lists and combines them into a single list.

## Examples

```
> concat(["a", ""], ["b", "c"])
[
  "a",
  "",
  "b",
  "c",
]

# Can do multiple lists of mixed types, arguments can also be empty lists
concat([], [1, "a"], [[3], "c"])
[
  1,
  "a",
  [
    3,
  ],
  "c",
]
```