{
public abstract class Item
{
protected string item_name; protected double item_price; protected int item_quantity; private double total_price;
public Item(string name, double price, int quantity) { this.item_name = name;
this.item_price = price; this.item_quantity = quantity;
this.total_price = this.item_price * this.item_quantity;
}
public abstract double getTotalPrice();
public abstract void setPayment(double amount);
}