JAVA

deque in java

Deque<Integer> arrayQueue = new ArrayDeque<>();
Deque<Integer> linkedListQueue = new LinkedList<>();

// these operations are useful and same on both.
arrayQueue.push()/addFirst()/addLast();

arrayQueue.remove()/removeFirst()/removeLast()/pop();

arrayQueue.peek()/peekFirst()/peekLast()/size()/

dequeue in java

// Java program to demonstrate the
// iteration of elements in deque
  
import java.util.*;
public class ArrayDequeDemo {
    public static void main(String[] args)
    {
        // Initializing an deque
        Deque<String> dq
            = new ArrayDeque<String>();
  
        // add() method to insert
        dq.add("For");
        dq.addFirst("Geeks");
        dq.addLast("Geeks");
        dq.add("is so good");
  
        for (Iterator itr = dq.iterator();
             itr.hasNext();) {
            System.out.print(itr.next() + " ");
        }
  
        System.out.println();
  
        for (Iterator itr = dq.descendingIterator();
             itr.hasNext();) {
            System.out.print(itr.next() + " ");
        }
    }
}

Java How to use Deque?

// Array implementation of Deque
Deque<String> animal1 = new ArrayDeque<>();

// LinkedList implementation of Deque
Deque<String> animal2 = new LinkedList<>();