TreeSet descendingIterator() method in Java with Examples
Last Updated :
31 Oct, 2023
Improve
The descendingIterator() method of java.util.TreeSet<E> class is used to return an iterator over the elements in this set in descending order.
Syntax:
public Iterator descendingIterator()
Return Value: This method returns an iterator over the elements in this set in descending order.
Below are the examples to illustrate the descendingIterator() method
Example 1:
// Java program to demonstrate
// descendingIterator() method
// for Integer value
import java.util.*;
public class GFG1 {
public static void main(String[] argv) throws Exception
{
try {
// create tree set object
TreeSet<Integer> treeadd = new TreeSet<Integer>();
// populate the TreeSet using add() method
treeadd.add(10);
treeadd.add(20);
treeadd.add(30);
treeadd.add(40);
// Print the TreeSet
System.out.println("TreeSet: " + treeadd);
// create descending iterator
// using descendingIterator() method
Iterator<Integer>
iterator = treeadd.descendingIterator();
System.out.println("\nValues using DescendingIterator:");
// printing the integrated value
while (iterator.hasNext()) {
System.out.println("Value : "
+ iterator.next());
}
}
catch (NullPointerException e) {
System.out.println("Exception thrown : " + e);
}
}
}
Output
TreeSet: [10, 20, 30, 40] Values using DescendingIterator: Value : 40 Value : 30 Value : 20 Value : 10
Example 2:
// Java program to demonstrate
// descendingIterator() method
// for String value
import java.util.*;
public class GFG1 {
public static void main(String[] argv) throws Exception
{
try {
// create tree set object
TreeSet<String> treeadd = new TreeSet<String>();
// populate the TreeSet using add() method
treeadd.add("A");
treeadd.add("B");
treeadd.add("C");
treeadd.add("D");
// Print the TreeSet
System.out.println("TreeSet: " + treeadd);
// create descending iterator
// using descendingIterator() method
Iterator<String>
iterator = treeadd.descendingIterator();
System.out.println("\nValues using DescendingIterator:");
// printing the integrated value
while (iterator.hasNext()) {
System.out.println("Value : "
+ iterator.next());
}
}
catch (Exception e) {
System.out.println("Exception thrown : " + e);
}
}
}
Output
TreeSet: [A, B, C, D] Values using DescendingIterator: Value : D Value : C Value : B Value : A
