---
title: "map values to guid seeds · RUAL Documentation"
description: "Maps each value in the array through the deterministic GUID seed hash. Produces an array of GUIDs where each GUID is derived from the corresponding valu…"
canonical: https://docs.rual.nl/block-types/array/array_map_guid_seed
language: en
---

# map values to guid seeds

This block is part of the [`array`](https://docs.rual.nl/block-types/array) group and was last modified in core [`v14.0.5`](https://docs.rual.nl/core-versions/140005).

Maps each value in the array through the deterministic GUID seed hash. Produces an array of GUIDs where each GUID is derived from the corresponding value. Much faster than using array map with a custom function.

- array required `array`

- array `array`

Replaces each item with the lowercase hex SHA-256 hash of the item coerced to a string using JavaScript String() rules (null becomes "null", arrays join elements with commas, plain objects become "[object Object]"). Deterministic: equal values always produce the same hash. Non-array input outputs [].

| `hash` |
| --- |
| `guid seed` |

A typical wiring for [map values to guid seeds](https://docs.rual.nl/block-types/array/array_map_guid_seed): [add suffix to values](https://docs.rual.nl/block-types/array/array_add_suffix) feeds the `array` pin; the `array` out pin feeds [storage left join exists](https://docs.rual.nl/block-types/storage/function_storage_left_join_exists).

![Studio canvas example for the map values to guid seeds block: typical wiring for map values to guid seeds.](https://docs.rual.nl/canvas-examples/array_map_guid_seed.png)

### Commonly used with

In production blueprints, this block is most often wired together with:

- [add suffix to values](https://docs.rual.nl/block-types/array/array_add_suffix): feeds into this block. Appends a suffix to each value in the array.

- [storage left join exists](https://docs.rual.nl/block-types/storage/function_storage_left_join_exists): this block feeds into it. Left joins a boolean field into the given array based on whether a document exists in the storage for each corresponding GUID. Sets the field to true when found, false when not.

### Version history

Introduced in [`v14.0.5`](https://docs.rual.nl/core-versions/140005).