# Array.reduce

## Function

Accumulate array elements from left to right.

## Syntax

```bt
array.reduce(callback, initial)
```

## Parameters

| Parameters | Type | Required | Default value | Description |
| ------ | ------ | ------ | ------ | ------ |
| callback | Fn | No | Empty | The callback signature is fn(acc, value, index, current). |
| initial | Any | No | First element | Initial accumulated value. |

## Return value

| Type | Description |
| ------ | ------ |
| Any | Returns the final cumulative value. |

## Example

```bt
items = [1, 2, 3]
result = items.reduce(fn(acc, value) { acc + value }, 0)

// Output: 6
print result
```

## Notes

- An error will be reported when initial is not provided for an empty array.