Update Queue_Learn.java

Author: tridibsamanta

Queue_Learn.java

@@ -10,146 +10,149 @@
 public class Queue_Learn {
 
 	public static void main(String[] args) {
-		
+
 		/*
-		 * The 'Queue' interface extends 'Collection' interface and declares the behaviour of a queue.
-		 * 'Queue' being an interface needs a class which provides implementation to its methods
-		 * and also that we can create objects of that class. 'LinkedList' and 'PriorityQueue' 
-		 * are the most commonly used classes used while creating a queue object.
+		 * The 'Queue' interface extends 'Collection' interface and declares the
+		 * behaviour of a queue. 'Queue' being an interface needs a class which provides
+		 * implementation to its methods and also that we can create objects of that
+		 * class. 'LinkedList' and 'PriorityQueue' are the most commonly used classes
+		 * used while creating a queue object.
 		 */
-		
+
 		/*
-		 * 'LinkedList' class extends 'AbstractSequentialList' class and implements the 'List',
-		 * 'Queue' and 'Deque' interfaces.
+		 * 'LinkedList' class extends 'AbstractSequentialList' class and implements the
+		 * 'List', 'Queue' and 'Deque' interfaces.
 		 */
-		
+
 		Queue<Integer> demoQueue = new LinkedList<>();
-		
+
 		/*
-		 *  Add an element to the queue
-		 *  
-		 *  boolean add(E obj)		: Declared in the Collection interface. Adds object to the collection.
-		 *                            Returns true if object was added, otherwise returns false.
-		 *                            
-		 *  boolean offer(E obj)	: Declared in the Queue interface. Adds object to the queue.
-		 *                            Returns true if object was added, otherwise returns false.                    
+		 * Add an element to the queue
+		 * 
+		 * boolean add(E obj) : Declared in the Collection interface. Adds object to the
+		 * collection. Returns true if object was added, otherwise returns false.
+		 * 
+		 * boolean offer(E obj) : Declared in the Queue interface. Adds object to the
+		 * queue. Returns true if object was added, otherwise returns false.
 		 */
-		
-		demoQueue.add(30); 
+
+		demoQueue.add(30);
 		// demoQueue = [30]
-		
-		demoQueue.add(10); 
+
+		demoQueue.add(10);
 		// demoQueue = [30, 10]
-		
-		demoQueue.add(50); 
+
+		demoQueue.add(50);
 		// demoQueue = [30, 10, 50]
-	
+
 		System.out.println("demoQueue = " + demoQueue); // demoQueue = [30, 10, 50]
-		
-		demoQueue.offer(20); 
+
+		demoQueue.offer(20);
 		// demoQueue = [30, 10, 50, 20]
-		
-		demoQueue.offer(40); 
+
+		demoQueue.offer(40);
 		// demoQueue = [30, 10, 50, 20, 40]
-		
+
 		System.out.println("demoQueue = " + demoQueue); // demoQueue = [30, 10, 50, 20, 40]
-		
+
 		/*
-		 *  Remove an element from the queue
-		 *  
-		 *  E remove()	: Declared in the Queue interface. Removes the element at the head
-		 *  			  of the queue returning the element in the process. It throws
-		 *                NoSuchElementException if the queue is empty.
+		 * Remove an element from the queue
+		 * 
+		 * E remove() : Declared in the Queue interface. Removes the element at the head
+		 * of the queue returning the element in the process. It throws
+		 * NoSuchElementException if the queue is empty.
 		 */
-		
-		demoQueue.remove(); 
+
+		demoQueue.remove();
 		// demoQueue = [10, 50, 20, 40]
-		
+
 		System.out.println("demoQueue = " + demoQueue); // demoQueue = [10, 50, 20, 40]
-		
-		int removedElement = demoQueue.remove(); 
+
+		int removedElement = demoQueue.remove();
 		// demoQueue = [50, 20, 40]
-		
+
 		System.out.println("Element removed = " + removedElement); // Element removed = 10
-		
+
 		/*
-		 *  Get the element at the head of the queue
-		 *  
-		 *  E peek()	: Declared in the Queue interface. Returns the element at the head
-		 *  			  of the queue. It returns null if the queue is empty.
+		 * Get the element at the head of the queue
+		 * 
+		 * E peek() : Declared in the Queue interface. Returns the element at the head
+		 * of the queue. It returns null if the queue is empty.
 		 */
-		
+
 		int headElement = demoQueue.peek();
 		// demoQueue = [50, 20, 40]
-		
+
 		System.out.println("Head element = " + headElement); // Head element = 50
-		
+
 		/*
-		 *  Get & remove the element at the head of the queue
-		 *  
-		 *  E poll()	: Declared in the Queue interface. Returns the element at the head of the queue, 
-		 *                removing the element in the process. It returns null if the queue is empty.
+		 * Get & remove the element at the head of the queue
+		 * 
+		 * E poll() : Declared in the Queue interface. Returns the element at the head
+		 * of the queue, removing the element in the process. It returns null if the
+		 * queue is empty.
 		 */
-		
+
 		headElement = demoQueue.poll();
 		// demoQueue = [20, 40]
-		
+
 		System.out.println("Head element = " + headElement); // Head element = 50
-		
+
 		demoQueue.poll();
 		// demoQueue = [40]
-		
+
 		System.out.println("demoQueue = " + demoQueue); // demoQueue = [40]
-		
+
 		/*
-		 *  Get the count of elements present in the queue
-		 *  
-		 *  int size()	: Declared in the Collection interface. Returns the number of elements 
-		 *                held in the invoking collection.
+		 * Get the count of elements present in the queue
+		 * 
+		 * int size() : Declared in the Collection interface. Returns the number of
+		 * elements held in the invoking collection.
 		 */
-		
+
 		int queueSize = demoQueue.size();
-		
+
 		System.out.println("Size = " + queueSize); // Size = 1
-		
+
 		/*
-		 *  Check if queue is empty or not
-		 *  
-		 *  boolean isEmpty()	: Declared in the Collection interface. Returns true if the 
-		 *                        invoking collection is empty. Otherwise, returns false.
+		 * Check if queue is empty or not
+		 * 
+		 * boolean isEmpty() : Declared in the Collection interface. Returns true if the
+		 * invoking collection is empty. Otherwise, returns false.
 		 */
-		
+
 		if (demoQueue.isEmpty())
 			System.out.println("Queue is empty !");
 		else
 			System.out.println("Queue is not empty !");
-		
+
 		/*
-		 *  Check if an object is present the queue
-		 *  
-		 *  boolean contains(Object obj)	: Declared in the Collection interface. Returns true if obj 
-		 *                                    is an element of the invoking collection. Otherwise, returns false.
+		 * Check if an object is present the queue
+		 * 
+		 * boolean contains(Object obj) : Declared in the Collection interface. Returns
+		 * true if obj is an element of the invoking collection. Otherwise, returns
+		 * false.
 		 */
-		
+
 		int value = 40;
-		
+
 		if (demoQueue.contains(value))
 			System.out.println("Queue contains " + value);
 		else
 			System.out.println("Queue does not contain " + value);
-		
+
 		/*
-		 *  Clear the queue
-		 *  
-		 *  void clear()	: Declared in the Collection interface. Removes all elements 
-		 *                    from the invoking collection.
+		 * Clear the queue
+		 * 
+		 * void clear() : Declared in the Collection interface. Removes all elements
+		 * from the invoking collection.
 		 */
-		
+
 		demoQueue.clear();
 		// demoQueue = []
-		
+
 		System.out.println("demoQueue = " + demoQueue); // demoQueue = []
-		
+
 	}
 
 }