Printing circular queue

Question

How do we print circular queue in the below mentioned code. After the queue is full and we remove one item and the insert the next item which comes at index 0. How do we print it then?. How do we print circular queue in the below mentioned code.

class GQueue <T extends Object>
{
    T[] arr;
    int size;
    int front;
    int rear;
    int length;

    GQueue(int size)
    {
        this.size=size;
        arr=(T[])new Object[this.size];
        front=-1;
        rear=-1;
        length=arr.length;
    }

    void EnQueue(T data)
    { 
            if(isFull())
            {
                System.out.println("Queue full");
                return;
            }

                else if(isEmpty())
                  front=rear=0;
                else 
                 rear = (rear+1)%length;

             arr[rear]=data;
    }

    void DeQueue()
    {
        if(isEmpty())
           return;
        else if (front==rear)
        {
           front=rear=-1;
        }
        else 
           front=(front+1)%length;

    }

    T peek()
    {

        return arr[front];
    }

    boolean isEmpty()
    {
        if(front==-1 && rear==-1)
        return true;
        else 
            return false;


    }

    boolean isFull()
    {
        if( (rear+1) % length==front)
            return true;
        else 
            return false;

    }

    void print()
    {
        for(int i=front;i<=rear;i++)
        {
         System.out.print(arr[i]+" ");  
        }
         System.out.println();  
    }
}





public class GenericQueue {

public static void main(String[] args) {
    GQueue<Integer> gq = new GQueue<Integer>(10);
    gq.EnQueue(1);
    gq.EnQueue(2);
    gq.EnQueue(3);
    gq.EnQueue(4);
    gq.EnQueue(5);
    gq.EnQueue(6);
    gq.EnQueue(7);
    gq.EnQueue(8);
    gq.EnQueue(9);
    gq.EnQueue(10);


    gq.print();
    gq.DeQueue();
    gq.EnQueue(11);
    gq.print();
}

}

Answer 1

void print(){
    if (!isEmpty()) {
        int i = front;
        do {
            System.out.print(" " + arr[i];
            i = ++i % arr.length;
        while (i != rear);
    }
}

Not tested, but I think it's right, or at least gives the general idea.