The reverseOrder() method of Comparator Interface in Java returns a comparator that use to compare Comparable objects in reverse of natural order. The returned comparator by this method is serializable and throws NullPointerException when comparing null.
Syntax:
static <T extends Comparable<T>>
Comparator<T> reverseOrder()
Parameters: This method accepts nothing.
Return value: This method returns a comparator that imposes the reverse natural ordering on Comparable objects.
Below programs illustrate reverseOrder() method:
Program 1:
Java
// Java program to demonstrate// Comparator.reverseOrder() methodimport java.util.Arrays;import java.util.Comparator;import java.util.List;public class GFG { public static void main(String... args) { List<Integer> values = Arrays.asList(212, 324, 435, 566, 133, 100, 121); // reverseOrder is a static method values.sort(Comparator.reverseOrder()); // print sorted number based on reverse order System.out.println(values); }} |
The output printed on console of IDE is shown below.
Output:
Program 2:
Java
// Java program to demonstrate// Comparator.reverseOrder() methodimport java.util.Arrays;import java.util.Comparator;import java.util.List;public class GFG { public static void main(String... args) { List<String> stringList = Arrays.asList("Aman", "Kajal", "Joyita", "Das"); System.out.println("Before sorting:"); stringList.forEach(System.out::println); stringList.sort(Comparator.reverseOrder()); System.out.println("\nAfter sorting:"); stringList.forEach(System.out::println); }} |
The output printed on console is shown below.
Output:
References: https://docs.oracle.com/javase/10/docs/api/java/util/Comparator.html#reverseOrder()
