How to discard and swap items in java?

[greenarcher]

What is the correct code for me to discard the item one, then put item two in item one's place, item three in item two's place, item four in item three's place, and for item five, it will be the new equipped item.

it should also return the discarded item at the end. Thanks

PHP Code:

public void equip (Item e)
    {
        if (itemOne == null)
        {
            itemOne = e;
            itemCounter+= 1;
        }
        
        else if (itemTwo == null)
        {
            itemTwo = e;
             itemCounter+= 1;
        }
            
        else if (itemThree == null)
        {
            itemThree = e;
            itemCounter+= 1;
        }
        else if (itemFour == null)
        {
            itemFour= e;
            itemCounter+= 1;
        }
            
        else if (itemFive == null)
        {
            itemFive = e;
            itemCounter+= 1;
        }
            
    }
    
    /**
     * The swap() method enables the Avatar to discard the Item in the first position of his/her belt,
     * advance the remaining Items in his/her belt one position forward, then place a new Item 
     * in the last position of his/her belt. 
     * 
     * @param e - : the Item to be added to the Avatar's belt
     * @param return the name of the Item discarded from the Avatar's belt
     */
    public String swap (Item e)
    {
        ?????

    } 


[Philip M]

This is the JavaScript forum. Java and Javascript are entirely different programming languages, in spite of the confusingly similar names. Rather like Austria and Australia! Ask a mod to move this thread to the right forum.

[AndrewGSW]

You should post in the correct forum firstly: this is the JavaScript forum, not java.

You also need to wrap your code in [CODE ] [/ CODE] tags (without the spaces). Highlight your code and press the hash # button when creating your post.

[VIPStephan]

What the others said, plus: if you post any code please put it in between [CODE][/CODE] tags. It makes scanning your posts much easier. You can do this by clicking the small ‘#’ icon above the reply field.

[Fou-Lu]

This behaviour is best done using a collection such as a LinkedList. The LinkedList includes the Deque and Queue interfaces, so you can easily treat it as a queue or a stack.
A quick example:

PHP Code:

import java.util.LinkedList;


public class QueueExample<T> extends LinkedList<T>
{    
    public T equip(T obj)
    {
        T result = this.pollFirst();
        this.offerLast(obj);
        return result;
    }
        
    public static void main(String[] argv)
    {
        QueueExample<Item> qe = new QueueExample<Item>();
        qe.add(new Item());
        qe.add(new Item());
        qe.add(new Item());
        qe.add(new Item());
        qe.add(new Item());
        
        System.out.println(qe);
        System.out.println("Removed: " + qe.equip(new Item()).toString());
        System.out.println(qe);
        System.out.println("Removed: " + qe.equip(new Item()).toString());
        System.out.println(qe);
    }
    
}

class Item
{
    private static int iCnt = 0;
    private int i;
    
    public Item()
    {
        this.i = ++Item.iCnt;
    }
    
    public String toString()
    {
        return "Item[" + this.i + "]";
    }
} 


I just keep making new ones, so my numbers keep counting up. But if you want you can cycle the list by offering the polledfirst object after you push the new item on the queue.