m323/01/ShoppingCartImperative.java

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

public class ShoppingCartImperative {
  private List<String> items = new ArrayList<>();
  private boolean bookAdded = false;

  public void addItem(String item) {
    items.add(item);
    if (item.toLowerCase().contains("book")) {
      bookAdded = true;
    } else {
      bookAdded = false;
    }
  }

  public void removeItem(String item) {
    items.remove(item);
    for (String remainingItem : items) {
      if (remainingItem.toLowerCase().contains("book")) {
        bookAdded = true;
        return;
      } else {
        bookAdded = false;
      }
    }
  }

  public List<String> getItems() {
    return new ArrayList<>(items);
  }

  public double getDiscount() {
    return bookAdded ? 5 : 0;
  }

  public static void main(String[] args) {
    ShoppingCartImperative cart = new ShoppingCartImperative();
    cart.addItem("Apple");
    cart.addItem("Java Book");
    System.out.println("Items: " + cart.getItems());
    System.out.println("Discount: " + cart.getDiscount());

    cart.removeItem("Java Book");
    System.out.println("Items after removal: " + cart.getItems());
    System.out.println("Discount after removal: " + cart.getDiscount());
  }
}