retainWhere method

@override void retainWhere(bool test(E e))

Removes all elements of this set that fail to satisfy test.

final characters = <String>{'A', 'B', 'C'};
characters.retainWhere(
    (element) => element.startsWith('B') || element.startsWith('C'));
print(characters); // {B, C}

Implementation

@override
void retainWhere(bool Function(E e) test) {
  final length = super.length;
  super.retainWhere(test);
  if (length != super.length) {
    notifyListeners();
  }
}