Question

I need to store the following line items on a receipt: quantity, description, upc, and price.

What is the best method in Java to store these? I need to print them to an output at some point by line, just like a receipt printer would. The number of elements in the collection should be arbitrary though because I will be adding and deleting elements.

5 item1 new item 324234  $4.99
1 item2 dish soap 34235346 $6.33

..and so on

Answer 1

I would think about creating some objects that would reflect the items you want to represent. For example, perhaps you might have a Receipt object that has a List of ReceiptItems.

public class Receipt {
    private List<LineItem> receiptItems;

    // ... 

    public void add(LineItem lineItem) {
        // be mindful of handling duplicates if needed
        receiptItems.add(lineItem); 
    }

}

Each of your items would contain the values you wish to keep track of

public class LineItem {
    private int quantity;
    private String description;
    private String upc;
    private BigDecimal price; // depending on the accuracy you need, you might be able to get away with double

    // ...

    public String getDescription() {
        return description;
    }

    // ... add more getters to your heart's content ...
}

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UPDATE:

To access the private methods, you would create a few getters or action methods. I’ve added a few above as an example.