# Regex modifier

## Function

Description of the flags supported by regex(pattern, flags). The current source code uses i, m, s to participate in compilation, and g is used by replace to determine whether to replace globally.

## Syntax

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

## Parameters

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

## Return value

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

## Example

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

// Output: true
print result
```

## Notes

- g does not participate in regex compilation, and only controls the number of substitutions when Regex.replace and String.replace receive Regex.