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no-empty-class

docs/src/rules/no-empty-class.md

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Disallows empty character classes in regular expressions.

::: important This rule was removed in ESLint v1.0.0 and replaced by the 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:

::: incorrect

js
var foo = /^abc[]/;

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

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

:::

Examples of correct code for this rule:

::: correct

js
var foo = /^abc/;

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

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

:::