# Array.keys

## Function

Returns an array of array subscripts.

## Syntax

```bt
array.keys()
```

## Parameters

No parameters.

## Return value

| Type | Description |
| ------ | ------ |
| Array | Returns an array of integers from 0 to len - 1. |

## Example

```bt
items = ['a', 'b']
result = items.keys()

// Output: [0,1]
print result
```

## Notes

- The original array will not be modified.