In this article, we will see how to sort ArrayList elements in descending order using sort(List list, Collections.reverseOrder()) method.

Examples:
Input:    23, 54, 32, 56, 78, 65
Output: 78, 65, 56, 54, 32, 23

Input:    Microsoft, Vmware, Salesforce, Apple, Facebook
Output: Vmware, Salesforce, Microsoft, Facebook, Apple

Example 1:

The below programs shows how to use sort(List list,Collections.reverseOrder()) to sort ArrayList elements in descending order. Here the elements are of Integer type.

import java.util.ArrayList;
import java.util.Collections;

public class ArrayListSortDescendingExample {

        public static void main(String[] args) {
                ArrayList numbers = new ArrayList<>();
                numbers.add(23);
                numbers.add(54);
                numbers.add(32);
                numbers.add(56);
                numbers.add(78);
                numbers.add(65);

                System.out.println("Elements before sorting : " + numbers);
                Collections.sort(numbers, Collections.reverseOrder());
                System.out.println("After sorting in descending order : " + numbers);

        }
}

Output:

Elements before sorting : [23, 54, 32, 56, 78, 65]
After sorting in descending order : [78, 65, 56, 54, 32, 23]

Example 2:

Let’s look at the program.

import java.util.ArrayList;
import java.util.Collections;

public class ArrayListSortDescendingDemo {

        public static void main(String[] args) {
                ArrayList companies = new ArrayList<>();
                companies.add("Microsoft");
                companies.add("Vmware");
                companies.add("Salesforce");
                companies.add("Apple");
                companies.add("Facebook");

                System.out.println("Companies before sorting : " + companies);
                Collections.sort(companies, Collections.reverseOrder());
                System.out.println("ArrayList Elements after sorting in descending order : " + companies);
        }
}

Output:

Companies before sorting : [Microsoft, Vmware, Salesforce, Apple, Facebook]
ArrayList Elements after sorting in descending order : [Vmware, Salesforce, Microsoft, Facebook, Apple]

In this article, we saw how to use Collections.reverseOrder().

Further Reading:

ArrayList Reference.