# Regex empty match

## Function

Describes an expression that may match the empty string.

## Syntax

```bt
regex(pattern, flags)
```

## Parameters

| Parameters | Type | Required | Default value | Description |
| ------ | ------ | ------ | ------ | ------ |
| pattern | String | No | '' | May contain empty matching quantifiers such as *, ?, {0,n}. |
| flags | String | No | '' | Regular flags. |

## Return value

| Type | Description |
| ------ | ------ |
| Regex | Returns a Regex object. |

## Example

```bt
rule = regex('^.*$', '')
result = rule.test('')

// Output: true
print result
```

## Notes

- Empty matching may produce unintuitive results in replace and match. The boundaries should be clear when writing business rules.