ArrayDeque descendingIterator() Method in Java
Last Updated :
10 Dec, 2018
The Java.util.ArrayDeque.descendingIterator() method is used to return an iterator of the same elements as the ArrayDeque but in the reverse order.
Syntax:
Iterator iterate_value = Array_Deque.descendingIterator();
Parameters: The method does not take any parameter.
Return Value: The method iterates over the elements of the deque and returns the values(iterators) in reverse order.
Below programs illustrate the Java.util.ArrayDeque.descendingIterator() method:
Program 1:
Java
// Java code to illustrate descendingIterator()
import java.util.*;
public class ArrayDequeDemo {
public static void main(String args[])
{
// Creating an empty ArrayDeque
Deque<String> de_que = new ArrayDeque<String>();
// Use add() method to add elements into the Queue
de_que.add("Welcome");
de_que.add("To");
de_que.add("Geeks");
de_que.add("4");
de_que.add("Geeks");
// Displaying the ArrayDeque
System.out.println("ArrayDeque: " + de_que);
// Creating a desc_iterator
Iterator value = de_que.descendingIterator();
// Displaying the values after iterating through the Deque
// in reverse order
System.out.println("The iterator values are: ");
while (value.hasNext()) {
System.out.println(value.next());
}
}
}
Output:
ArrayDeque: [Welcome, To, Geeks, 4, Geeks]
The iterator values are:
Geeks
4
Geeks
To
Welcome
Program 2:
Java
// Java code to illustrate descendingIterator()
import java.util.*;
public class ArrayDequeDemo {
public static void main(String args[])
{
// Creating an empty ArrayDeque
Deque<Integer> de_que = new ArrayDeque<Integer>();
// Use add() method to add elements into the Queue
de_que.add(10);
de_que.add(15);
de_que.add(30);
de_que.add(20);
de_que.add(5);
// Displaying the ArrayDeque
System.out.println("ArrayDeque: " + de_que);
// Creating a desc_iterator
Iterator value = de_que.descendingIterator();
// Displaying the values after iterating through the Deque
// in reverse order
System.out.println("The iterator values are: ");
while (value.hasNext()) {
System.out.println(value.next());
}
}
}
Output:
ArrayDeque: [10, 15, 30, 20, 5]
The iterator values are:
5
20
30
15
10