Comparator<T> constructor

An abstract class that imposes a total ordering on a collection of objects of type T.

A Comparator can be used to:

• Sort lists (List.sort(comparator)).
• Control ordering in sorted collections (e.g., custom trees or ordered maps).
• Provide alternate sort logic for types that don’t implement Comparable.

This Dart class is inspired by Java's java.util.Comparator.

📌 Example Usage

final Comparator<String> byLength = Comparator.comparing((s) => s.length);

final names = ['Alice', 'Bob', 'Christina'];
names.sort(byLength.compare);

print(names); // [Bob, Alice, Christina]

You can also chain comparators:

final byLengthThenAlphabet = Comparator.comparing((s) => s.length)
    .thenComparing(Comparator.naturalOrder());

final list = ['Tom', 'Ann', 'Tim', 'Jim', 'Alex'];
list.sort(byLengthThenAlphabet.compare);

print(list); // [Ann, Jim, Tom, Tim, Alex]