---
title: no-empty-class - Rules
layout: doc
edit_link: https://github.com/eslint/eslint/edit/master/docs/rules/no-empty-class.md

---
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# no-empty-class: disallow empty character classes in regular expressions

(removed) This rule was **removed** in ESLint v1.0 and **replaced** by the [no-empty-character-class](no-empty-character-class) rule.

Empty character classes in regular expressions do not match anything and can result in code that may not work as intended.

```js
var foo = /^abc[]/;
```

## Rule Details

This rule is aimed at highlighting possible typos and unexpected behavior in regular expressions which may arise from the use of empty character classes.

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

```js
var foo = /^abc[]/;

/^abc[]/.test(foo);

bar.match(/^abc[]/);
```

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

```js
var foo = /^abc/;

var foo = /^abc[a-z]/;

var bar = new RegExp("^abc[]");
```

## Version

This rule was introduced in ESLint 0.0.9 and removed in 1.0.0-rc-1.

## Resources

* [Documentation source](https://github.com/eslint/eslint/tree/master/docs/rules/no-empty-class.md)
