comparing<T, U extends Comparable<U>> static method

Comparator<T> comparing<T, U extends Comparable<U>>(
  1. U keyExtractor(
    1. T
    )
)

Creates a comparator based on a Comparable key extracted from each element.

Useful when sorting objects that have a comparable field but do not implement Comparable.

Example

class User {
  final int age;
  User(this.age);
}

final byAge = Comparator.comparing<User, int>((user) => user.age);
final users = [User(40), User(20)];
users.sort(byAge.compare);
print(users.map((u) => u.age)); // [20, 40]

Implementation

static Comparator<T> comparing<T, U extends Comparable<U>>(U Function(T) keyExtractor) => _ComparingComparableComparator(keyExtractor);