v1.12.2/website/docs/language/functions/setintersection.mdx

---
page_title: setintersection function reference - Functions - Configuration Language
description: |-
  The setintersection function takes multiple arrays and produces a single array
  containing only the elements that all of the given arrays have in common.
---

# `setintersection` function reference

This topic provides reference information about the `setintersection` function,
which computes the intersection of the specified sets. 

## Introduction

The `setintersection` function takes multiple sets and produces a single set
containing only the elements that all of the given sets have in common.
In other words, `setintersection` computes the intersection of the sets. 
Refer to Wikipedia's [Intersection (set
theory)](https://en.wikipedia.org/wiki/Intersection_\(set_theory\)) article
for a mathematical explanantion of set theory intersection. 

## Syntax

Use the `setintersection` function with the following syntax:

```hcl
setintersection(sets...)
```

Replace `sets...` with a comma-delimited list of sets such as `["a","b"], ["a","c","g"]`. The elements of
the different sets do not have to be the same type. 

The `setintersection` result is an unordered set.

## Example use cases

This example passes in sets of strings and returns a set with one element.

```hcl
> setintersection(["a", "b"], ["b", "c"], ["b", "d"])
[
  "b",
]
```

This example passes in number sets of different sizes and returns a set with two elements.

```hcl
> setintersection([3,3.3,4], [4,3.3,65,99], [4.0,3.3])
toset([
  3.3,
  4,
])
```

This examples pass in sets of different lengths and element types. 
The result is a set of two string elements.

```hcl
> setintersection(["bob","jane",3], ["jane",3,"ajax",10], ["3","jane",26,"nomad"])
toset([
  "3",
  "jane",
])
```

## Related Functions

* [`contains`](/terraform/language/functions/contains) tests whether a given list or set contains
  a given element value.
* [`setproduct`](/terraform/language/functions/setproduct) computes the _Cartesian product_ of multiple
  sets.
* [`setsubtract`](/terraform/language/functions/setsubtract) computes the _relative complement_ of two sets
* [`setunion`](/terraform/language/functions/setunion) computes the _union_ of
  multiple sets.