# disallow control characters in regular expressions (no-control-regex)

Control characters are special, invisible characters in the ASCII range 0-31. These characters are rarely used in JavaScript strings so a regular expression containing these characters is most likely a mistake.

## Rule Details

This rule disallows control characters in regular expressions.

Examples of **incorrect** code for this rule:

```js
/*eslint no-control-regex: "error"*/

var pattern1 = /\x1f/;
var pattern2 = new RegExp("\x1f");
```

Examples of **correct** code for this rule:

```js
/*eslint no-control-regex: "error"*/

var pattern1 = /\x20/;
var pattern2 = new RegExp("\x20");
```

## When Not To Use It

If you need to use control character pattern matching, then you should turn this rule off.

## Related Rules

* [no-div-regex](no-div-regex.md)
* [no-regex-spaces](no-regex-spaces.md)