# prefer_underscore_for_unused_callback_parameters

| Severity | Quick Fix | Options |
|:--------:|:---------:|:-------:|
|   Info   |    ❌     |   ❌    |

## Details

**DO** use `_` for unused callback parameters.

<Info> Since Dart 3.7.0, local parameters named `_` can be declared multiple times without collisions.</Info>

see: [effective-dart](https://dart.dev/effective-dart/style#prefer-using-_-__-etc-for-unused-callback-parameters) and
[wildcard variables](https://dart.dev/language/variables#wildcard-variables)

```dart title="Bad"
itemBuilder: (context, index) {
  return Text('Item $index');
}
```

```dart title="Good"
itemBuilder: (_, index) {
  return Text('Item $index');
}
```

## Usage

To enable the `prefer_underscore_for_unused_callback_parameters` rule, add `prefer_underscore_for_unused_callback_parameters` under `plugins > pyramid_lint > diagnostics` in your `analysis_options.yaml` file:

```yaml
plugins:
  pyramid_lint: <version>
    diagnostics:
      prefer_underscore_for_unused_callback_parameters: true
```