Object-Oriented MealOrder Code

Do not copy-n-paste this code, for reference only

MealOrder.java

import java.util.ArrayList;
import java.util.List;

public class MealOrder {

  List<MenuItem> items = new ArrayList<>();

  public MealOrder() {
  }

  public void addBurger(String burgerType) {
    items.add(new Burger(burgerType));
  }

  public void addDrink(String drinkType) {
    items.add(new Drink(drinkType));
  }

  public MealOrder(String burgerType) {
    addBurger(burgerType);
  }

  public MealOrder(String burgerType, String drinkSize) {
    addBurger(burgerType);
    addDrink(drinkSize);
  }

  public int price() {
    // loop over all items and sum their price
    int price = 0;
    for (MenuItem item: items) {
      price = price + item.price();
    }
    return price;
  }

}

Burger.java

public class Burger extends MenuItem {

  public static final String BURGER_CHEESE = "cheeseburger";
  public static final String BURGER_REGULAR = "regular";

  private String burgerType = "";

  public Burger(String newBurgerType) {
    burgerType = newBurgerType;
  }

  @Override
  public int price() {
    if (burgerType.equals(BURGER_REGULAR)) {
      return 5;
    } else if (burgerType.equals(BURGER_CHEESE)) {
      return 6;
    }
    return 0;
  }
}

Drink.java

public class Drink extends MenuItem {

  public static final String DRINK_REGULAR = "regular";
  public static final String DRINK_LARGE = "large";

  private String drinkSize = ""; // regular or large

  public Drink() {
  }

  public Drink(String theDrinkSize) {
    drinkSize = theDrinkSize;
  }

  @Override
  public int price() {
    if (drinkSize.equals(DRINK_REGULAR)) {
      return 1;
    } else if (drinkSize.equals(DRINK_LARGE)) {
      return 2;
    }
    return 0;
  }

}

MenuItem.java

public class MenuItem {

  public int price() {
    return 0;
  }

}