unused_field

The value of the field '{0}' isn't used.

The analyzer produces this diagnostic when a private field is declared but never read, even if it's written in one or more places.

The following code produces this diagnostic because the field _originalValue isn't read anywhere in the library:

class C {
  final String _originalValue;
  final String _currentValue;

  C(this._originalValue) : _currentValue = _originalValue;

  String get value => _currentValue;
}

It might appear that the field _originalValue is being read in the initializer (_currentValue = _originalValue), but that is actually a reference to the parameter of the same name, not a reference to the field.

If the field isn't needed, then remove it.

If the field was intended to be used, then add the missing code.

Unless stated otherwise, the documentation on this site reflects Dart 3.8.1. Page last updated on 2025-05-08. View source or report an issue.