Lab for Polymorphism, Equals, and More

String a = _____________________________; // your example
String b = _____________________________; // your example

System.out.println("a = "+a);
System.out.println("b = "+b);  // a and b should print the same
System.out.println("a.equals(b) is " + (a.equals(b)) ); // Should be TRUE
System.out.println("a == b is " + (a==b) ); // Should be FALSE

String a = "apple";
String b = "apple";
if (a == b) System.out.println( "Same" );   // prints "Same"

String A = a.toUpperCase();
String B = b.toUpperCase();
if (A == B) System.out.println( "Same" );   // doesn't print!

// Use same course id but with distinct strings,
// to catch errors in equals.
// equals should only compare course id, not course title (can differ)
Course a = new Course("01219111", "Intro to Programming", 3);
Course b = new Course(new String("01219111"), "Programming for Dummies", 3);
System.out.println("a = " + a);
System.out.println("b = " + b);
// Verify it works -- should be equal
if (a.equals(b)) System.out.println("a and b are equal");
else System.out.println("a and b are not equal");

// Verify that equals really tests the id (only)
// Create another course with different id but same title and credits.
Course c = new Course("01219112", "Intro to Programming", 3);
System.out.println("a = " + a);
System.out.println("c = " + c);
if (a.equals(c)) System.out.println("a and c are equal");
else System.out.println("a and c are not equal");

  import something;
  /**
   * The Course class.
   * @author Gill Bates
   */
  public class Course

/**
 * An item in the customer's order, including quantity.
 * @author your name
 */
public class OrderItem {
    /** id of the menu item (same id as in menu) */
    private int id;
    /** name of menu item */
    private String name;
    /** unit price of menu item */
    private double price;
    /** quantity of this item */
    private int quantity;

    /**
     * Initialize a new OrderItem, with quantity 1.
     * @param id menu item id
     * @param name menu item name
     * @param price is the unit price of menu item
     */
    public OrderItem(int id, String name, double price) {
        this(id, name, price, 1);  // invoke the other constructor

    }

    /**
     * Initialize a new OrderItem, with specified quantity.
     * @param id menu item id
     * @param name menu item name
     * @param price is the unit price of menu item
     * @param qnty is the quantity of item in the order
     */
    public OrderItem(/*TODO write the parameters */) {
        //TODO initialize the attributes
    }

OrderItem item1 = new OrderItem(12, "Pad Thai", 30.0);  // quantity is 1
item1.addQuantity(2);   // now total quantity is 3
printOrderItem(item1);

Orderitem item2 = new OrderItem(7, "Salad", 25.50, 2);
printOrderItem(item2);
// change quantity to 1
item2.setQuantity(1);
printOrderItem(item2);

// Add to order and compute the total
OrderItem[] myOrder = { item1, item2 };
System.out.println("Order contains:");
double total = 0.0;
for(OrderItem item: myOrder) {
    printOrderITem(item);
    total += item.getTotal();
}
System.out.printf("Total price: %.2f\n", total);

public static void printOrderItem(OrderItem item) {
    System.out.printf("%-24.24s %2d @ %6.2f %,8.2f\n", 
        item.getName(), item.getQuantity(), item.getPrice(), item.getTotal());
}

/**
 * An item in the customer's order, with 2-for-1 pricing.
 *
 * @author your name
 */
public class TwoForOneItem extends OrderItem {
    //NO attributes: they are in superclass

    /**
     * Initialize a new TwoForOneItem, with quantity 1.
     * @param id menu item id
     * @param name menu item name
     * @param price is the unit price of menu item
     */
    public TwoForOneItem(int id, String name, double price) {
        super(id, name, price);
    }

    /**
     * Initialize a new TwoForOneItem, with specified quantity.
     * @param id menu item id
     * @param name menu item name
     * @param price is the unit price of menu item
     * @param qnty is the quantity of item in the order
     */
    public TwoForOneItem(/* TODO */) {
        //TODO
    }

    /**
     * Return the total price of this item, using 2-for-1 pricing.
     * If the customer buys 2 then he pays for 1, buy 4 pay for 2.
     * But if he buys 3 then he still pays for 2.
     */
    @Override
    public double getTotal() {
        //TODO write this method
    }

OrderItem item1 = new OrderItem(7, "Salad", 25.5, 2); // no discount
printOrderItem(item1);

// SKE wants to compete with PizzaHut, so we have 2-for-1 promotion...
Orderitem item2 = new TwoForOneItem(1, "Large Veg. Pizza", 399.00);
// since its 2-for-1 lets buy more
item2.addQuantity(3);
printOrderItem(item2);

// Add to order and compute the total
OrderItem[] myOrder = { item1, item2 };
System.out.println("Order contains:");
double total = 0.0;
for(OrderItem item: myOrder) {
    printOrderItem(item);
    total += item.getTotal();
}
System.out.printf("Total price: %.2f\n", total);

OrderItem item1 = new OrderItem(7, "Salad", 25.5, 2); // no discount
Orderitem item2 = new TwoForOneItem(1, "Large Veg. Pizza", 399.00);
// since its 2-for-1 lets buy more
item2.addQuantity(3);

Order order = new Order();
order.addItem(item1);
order.addItem(item2);

// Display the order
System.out.println("Order contains:");
for( OrderItem item: order.getItems() ) {
    printOrderItem(item);
}
double total = order.getTotal();
System.out.printf("Total price: %.2f\n", total);