Circulare Implementation For Queue Using Array

QueueArrayCircular.java

// A class to represent a queue
class Queue
{
    int front, rear, size;
    int capacity;
    int array[];
      
    public Queue(int n) {
         capacity = n;
         front = size = 0; 
         rear = capacity - 1;
         array = new int[n];
    }
      
    // Queue is full when size becomes equal to the capacity 
    boolean isFull()
    {  return (size == capacity);
    }
      
    // Queue is empty when size is 0
    boolean isEmpty()
    {  return (size == 0); }
      
    // Method to add an item to the queue. It changes rear and size
    void enqueue( int item)
    {
        if (isFull()){
            System.out.println(" It's full ");
            return;
        }
        rear = (rear + 1)%capacity;
        array[rear] = item;
        size = size + 1;
        System.out.println(item + " enqueued to queue at index " + rear);
    }
      
    // Method to remove an item from queue. It changes front and size
    int dequeue()
    {
        if (isEmpty())
            return Integer.MIN_VALUE;
          
        int item = array[front];
        System.out.println( item + " dequeued at index " + front);
        front = (front + 1)%capacity;
        size = size - 1;
        return item;
    }
      
    // Method to get front of queue
    int front()
    {
        if (isEmpty())
            return Integer.MIN_VALUE;
          
        return array[front];
    }
       
    // Method to get rear of queue
    int rear()
    {
        if (isEmpty())
            return Integer.MIN_VALUE;
          
        return array[rear];
    }
    
    // Method to get rear of queue
    void status()
    {
        System.out.println(" Front :" + front);
        System.out.println(" Rear :" + rear );
    }
}
  
class Test
{
    public static void main(String[] args) 
    {
        Queue queue = new Queue(4);
           
        queue.enqueue(10);
        queue.enqueue(20);
        queue.enqueue(30);
        
        queue.dequeue();
        queue.dequeue();
            
        queue.enqueue(40);
        
        queue.status();
        
        queue.enqueue(50);
        queue.enqueue(60);
        
        queue.status();
        
        queue.enqueue(70);
        
        queue.dequeue();
        queue.dequeue();
            
        queue.status();
        
        queue.enqueue(70);
        
        queue.status();
       
        System.out.println("Front item is " + queue.front());
          
        System.out.println("Rear item is " + queue.rear());
    }
}