---
url: /docs/guide/usage/linter/rules/eslint/default-case.md
---

### What it does

Enforces that all `switch` statements include a `default` case,
unless explicitly marked with a configured comment.

### Why is this bad?

Without a `default` case, it is unclear whether the omission was
intentional or an oversight. Adding a `default` or a special comment
makes the code more explicit and reduces mistakes.

You may optionally include a `// no default` after the last case if there is
no default case. The comment may be in any desired case, such as `// No Default`.

Example configuration:

```json
{
  "default-case": ["error", { "commentPattern": "^skip\\sdefault" }]
}
```

### Examples

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

```js
switch (foo) {
  case 1:
    break;
}
```

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

```js
switch (a) {
  case 1:
    break;
  default:
    break;
}

switch (a) {
  case 1:
    break;
  // no default
}
```

## Configuration

This rule accepts a configuration object with the following properties:

### commentPattern

type: `string`

A regex pattern used to detect comments that mark the absence
of a `default` case as intentional.

Default value: `no default`.

Examples of **incorrect** code for this rule with the `{ "commentPattern": "^skip\\sdefault" }` option:

```js
switch (a) {
  case 1:
    break;
  // no default
}
```

Examples of **correct** code for this rule with the `{ "commentPattern": "^skip\\sdefault" }` option:

```js
switch (a) {
  case 1:
    break;
  // skip default
}
```

## How to use

## Version

This rule was added in v0.4.0.

## References