How to sort TreeSet in descending order in Java?

How to sort TreeSet in descending order in Java?

Last Updated : 22 Oct, 2020

Given a TreeSet in Java, task is to sort elements of TreeSet in Descending Order (descreasing order).
Examples:

Input : Set: [2, 3, 5, 7, 10, 20]
Output : Set: [20, 10, 7, 5, 3, 2]

Input : Set: [computer, for, geeks, hello]
Output : Set: [hello, geeks, for, computer]

Approach:
To make a TreeSet Element in decreasing order, simple use descendingSet() method which is used to change the order of TreeSet in reverse order
Below is the implementation of the above approach:

Java

// Java Program to print TreeSet in reverse Order
import java.util.TreeSet;

public class TreeSetDescending 
{

    public static void main(String[] args)
    {
        // Declare a treeset
        TreeSet<Object> ints = new TreeSet<Object>();
        ints.add(2);
        ints.add(20);
        ints.add(10);
        ints.add(5);
        ints.add(7);
        ints.add(3);

        // Initialize treeset with 
        // predefined set in reverse order
        // using descendingSet()
        TreeSet<Object> intsReverse =
            (TreeSet<Object>)ints.descendingSet();

        // Print the set
        System.out.println("Without descendingSet(): " + 
                                                 ints);
        System.out.println("With descendingSet(): " + 
                                           intsReverse);
    }
}

Output

Without descendingSet(): [2, 3, 5, 7, 10, 20]
With descendingSet(): [20, 10, 7, 5, 3, 2]

How to sort TreeSet in descending order in Java?

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