ArrayList Problem

[Chris G Johnson]

Hi,

I am trying to create a program that makes a list of food items in an array list that can be used to create food orders. I have started on the arraylist of food items but I don't understand how to calculate the price and how to store the orders. This is the code I have so far which I know is pretty pathetic at the minute:-

package myprojects.burgerbararraylista;
 
import java.awt.*;
import java.awt.event.*;
import java.util.*;
 
class BurgerBarArrayListA extends Frame {

public BurgerBarArrayListA() {
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
dispose();
System.exit(0);
}
Food f = new Food();
});
}
 
public static void main(String args[]) {
System.out.println("Starting BurgerBarArrayListA...");
BurgerBarArrayListA mainFrame = new BurgerBarArrayListA();
mainFrame.setSize(400, 400);
mainFrame.setTitle("BurgerBarArrayListA");
mainFrame.setVisible(true);
//addFoodItem("Regular Burger");
}
}
 
class Food
{

private ArrayList foodItems;

public Food()
{
foodItems = new ArrayList();
System.out.println("done");
}

public void addFoodItem(String description)
{
foodItems.add(description);
}

public int numberOfFoodItems()
{
return foodItems.size();
}

public void displayFoodItem(int foodID)
{
if(foodID < 0)
{
//This is not a valid food item so do nothing
}
else if (foodID < numberOfFoodItems())
 {
 //This is a valid foodID so print it
 System.out.println(foodItems.get(foodID));
 }
 else
 {
 //This is not a valid food item so do nothing
 }
}
}
 
class Order
{
private ArrayList orders;

public Order()
{
orders = new ArrayList();
}

public void addOrder(int orderID)
{
orders.add(orderID);
}

public int numberOfOrders();
{
return orders.size();
}
}

Thanks to anyone who can help!

[Randall Julian]

One problem here is that the add() method, as you've used it, expects an object and cannot take a primative.

This section works because String is a class and description is an object

public void addFoodItem(String description)
{
    foodItems.add(description);
}
 

This part fails to compile because int's are primatives not objects:

public void addOrder(int orderID)
{
    orders.add(orderID);
}

There may be other problems, but it seems like this is the first step. You can use the Integer class instead of an int to place a numerical object in an ArrayList - it seems like situations like this are what the wrapper classes are made for.
[ November 28, 2004: Message edited by: Randall Julian ]