# randIndex

> **randIndex**(`length`): `number`

Defined in: [packages/synapse-core/src/utils/rand.ts:39](https://github.com/FilOzone/synapse-sdk/blob/b11ef4f7e3c201d8bba29973a09628063e6547b1/packages/synapse-core/src/utils/rand.ts#L39)

Provides a random index into an array of supplied length (0 <= index < length)

## Parameters

| Parameter | Type | Description |
| ------ | ------ | ------ |
| `length` | `number` | exclusive upper boundary |

## Returns

`number`

a valid index