Explain De Queue With Syntax In Java

Below is the hierarchy diagram of Queue Interface, where Deque Interface extends the Queue Interface. Go through the below diagram to know high level ideas on Deque Interface. Syntax The deque interface is declared as, public interface Deque extends Queue Creating Deque Objects. Since Deque is an interface, objects cannot be created of the

In Java, the Deque interface is under java.util.Deque and it is a subtype of java.util.Queue interface. A Deque is a double-ended queue that means addition and deletion of the elements can be done from both the ends. The Deque can be used as a Queue or as Stack i.e First-in-first-out or Last-in-last-out. Below is the hierarchy of Deque interface

It throws an exception if this deque is empty. Syntax public Object removeLast 7. pollFirst Returns and removes the first element of this deque. Returns null if this deque is empty. Syntax public Object pollFirst 8. pollLast Returns and removes the last element of this deque. Returns null if this deque is empty. Syntax public

Deque Doubly ended queue is a data structure that allows you to insert and remove elements from both the ends. The Deque interface was introduced in Java 6 in java.util.collection package. The Deque interface extends the Queue interface just discussed. Hence, all methods provided by Queue are also available in the Deque interface.

The java.util.LinkedList class, while implementing java.util.List is a general-purpose implementation of java.util.Queue interface too operating on a FIFO First In, First Out principle. In the example below, with the offer method, the elements are inserted into the LinkedList. This insertion operation is called enqueue.

An In-depth Tutorial on Deque or Double-ended Queue in C. The tutorial explains What is Deque, Basic Operations, C amp Java Implementation and Applications Double-ended queue or simply called quotDequequot is a generalized version of Queue. The difference between Queue and Deque is that it does not follow the FIFO

Besides methods available in the Queue interface, the Deque interface also includes the following methods. addFirst - Adds the specified element at the beginning of the deque. Throws an exception if the deque is full. addLast - Adds the specified element at the end of the deque. Throws an exception if the deque is full. offerFirst - Adds the specified element at the beginning of the deque.

The dequeue is a double ended queue and data elements can be added or removed from either end. The dequeue in Java is implemented using the java.util.Deque interface which is a subtype of the java.util.Queue interface. A program that demonstrates some of the methods of a dequeue is given as follows . Example Live Demo

In Java, the Deque interface pronounced quotdeckquot, short for quotdouble-ended queue,quot is a subtype of the Queue interface that represents a linear collection that supports element insertion and removal

This is so because null is used as a special return value by various methods to indicated that the deque is empty. Deque implementations generally do not define element-based versions of the equals and hashCode methods, but instead inherit the identity-based versions from class Object. This interface is a member of the Java Collections Framework.