---
title: hash.cityhash64() function
description: hash.cityhash64() converts a string value to a 64-bit hexadecimal hash using the CityHash64 algorithm.
url: https://docs.influxdata.com/flux/v0/stdlib/contrib/qxip/hash/cityhash64/
estimated_tokens: 490
product: Flux
version: v0
---

# hash.cityhash64() function

-   Flux 0.192.0+
-   View InfluxDB support

`hash.cityhash64()` is a user-contributed function maintained by the [package author](#package-author-and-maintainer).

`hash.cityhash64()` converts a string value to a 64-bit hexadecimal hash using the CityHash64 algorithm.

##### Function type signature

```js
(v: A) => string
```

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

## Parameters

### v

(Required) String to hash.

## Examples

### Convert a string to a 64-bit hash using CityHash64

```js
import "contrib/qxip/hash"

hash.cityhash64(v: "Hello, world!")// Returns 2359500134450972198

```