# regex

## Function

Compiles a regular expression and returns a Regex object.

## Syntax

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

## Parameters

| Parameters | Type | Required | Default value | Description |
| ------ | ------ | ------ | ------ | ------ |
| pattern | String | No | '' | Regular expression text. |
| flags | String | No | '' | Flag; i ignores case, m is multi-line, s matches newline with dot, and g is used for global replacement by replace. |

## Return value

| Type | Description |
| ------ | ------ |
| Regex | Returns a regular object that can call test, match, and replace. |

## Example

```bt
rule = regex('BT', 'i')
result = rule.test('bt')

// Output: true
print result
```

## Notes

- A Chinese error is thrown when regular compilation fails.