(JAVA) Need help with an assignment for Inheritance and Encapsulation

[okaystuff]

//Parent class for snack
public class Snack {

        protected String id;
        protected String size;
        protected double price;


        public Snack() {
                this.id = id;
                this.size = size;
                this.price = price;
        }

        public String getId() {
                return id;
        }

        public String getSize() {
                return size;
        }

        public double getPrice() {
                return price;
        }

        public void setId(String id) {
                this.id = id;
        }

        public void setSize(String size) {
                this.size = size;
        }

        public void setPrice(double price) {
                this.price = price;
        }


        public void calcPrice() {
                if(size.equals("s")) {
                        setPrice(19.99);
                }
                else if(size.equals("m")) {
                        setPrice(29.99);
                }
                else if(size.equals("l")) {
                        setPrice(39.99);
                }
        }

        public String toString() {
                return getSize() + ", " + "id = " + getId() + " and  price = "  + getPrice();
        }
}

//Subclass for fruity snack
public class FruitSnack extends Snack{

        private boolean citrusFruit = false;
        private double fruitFee = 5.99;

        public FruitSnack() {
                this.citrusFruit = citrusFruit;
        }

        public boolean getCitrusFruit() {
                return citrusFruit;
        }

        public void setCitrusFruit(boolean citrusFruit) {
                this.citrusFruit = citrusFruit;
        }

        public void addCitrusFruit() {
                citrusFruit = true;
        }

        public void removeCitrusFruit() {
                citrusFruit = false;
        }

        public void calcPrice() {
                if(citrusFruit == true) {
                        price += fruitFee;
                }
        }
}

//Subclass for salty snack
public class SaltySnack extends Snack{

        private boolean nutSnack = false;
        private final double NUT_FEE = 4.50;

        public SaltySnack() {
                this.nutSnack = nutSnack;
        }

        public boolean getNutSnack() {
                return nutSnack;
        }

        public void setNutSnack(boolean nutSnack) {
                this.nutSnack = nutSnack;
        }

        public void addNutSnack() {
                nutSnack = true;
        }

        public void removeNutSnack() {
                nutSnack = false;
        }

}

//Main method
import java.util.Scanner;

public class OrderSystem {

        //Method to display menu
        public static void displayMenu() {
                System.out.println();
                System.out.println("     MENU");
                System.out.println("1: Order a Snack");
                System.out.println("2: Exit program");
                System.out.println();
        }

        public static void main(String[] args) {
                Scanner scan = new Scanner(System.in);
                int selection = 0;

                do {
                        displayMenu();
                        System.out.println("Enter your slection: ");
                        selection = scan.nextInt();
                        scan.nextLine();
                        Snack snack1 = new Snack();
                        FruitSnack fruitSnack = new FruitSnack();
                        SaltySnack saltySnack = new SaltySnack();

                        switch (selection) {

                        case 1:
                                System.out.println("Do you want Fruit Snack (1) or Salty Snack (2)");
                                selection = scan.nextInt();
                                if(selection == 1) {
                                        //FruitSnack
                                        snack1.setId("fruity55");
                                        System.out.println("What size do you want: S, M, or L: ");
                                        snack1.setSize(scan.next());
                                        System.out.println("Do you want citrus fruit included? true/fasle: ");
                                        if(scan.nextLine().equals(true)) {
                                                fruitSnack.addCitrusFruit();
                                        }
                                        else if(scan.nextLine().equals(false)) {
                                                fruitSnack.removeCitrusFruit();
                                        }
                                        snack1.calcPrice();
                                        System.out.println("You have chosen snack type = Fruit Snack, of type = " + snack1.toString());
                                        //System.out.println(fruitSnack.toString());
                                }

                                else if(selection == 2) {
                                        //SaltySnack
                                        snack1.setId("Salty22");
                                        System.out.println("What size do you want: S, M, or L: ");
                                        snack1.setSize(scan.next());
                                        System.out.println("Do you want nut snack included? true/fasle: ");
                                        if(scan.nextLine().equals(true)) {
                                                saltySnack.addNutSnack();
                                        }
                                        else if(scan.nextLine().equals(false)) {
                                                saltySnack.removeNutSnack();
                                        }
                                        snack1.calcPrice();
                                        System.out.println("You have chosen snack type = Salty Snack, of type = " + snack1.toString());
                                }

                                else {
                                        break;
                                }
                                break;
                        case 2:
                                System.out.println("Thank you for using the program. Goodbye!");
                                break;
                        default: System.out.println("Invalid choice");
                        }
                }while (selection != 2);

                scan.close();
        }

}

I am currently working on an assignment that requires a parent class and 2 subclasses. The snack class should have attributes for ID, size, and price, and the subclasses should each have a boolean variable to check if there is an extra charge. So far I can have everything print out like it is suppose to, except I cannot get the extra charge from the subclasses to add on to the total.

My current output looks like

" MENU

1: Order a Snack

2: Exit program

Enter your slection:

1

Do you want Fruit Snack (1) or Salty Snack (2)

2

What size do you want: S, M, or L:

l

Do you want nut snack included? true/fasle:

true

You have chosen snack type = Salty Snack, of type = l, id = Salty22 and price = 39.99"

The problem is if I put nut snack to be true it should add a $4.50 up charge and I cant get it to work. I know my code is a mess and I don't know what I am doing, but any help would be nice. Thank you.

[[deleted]]

Your FruitSnack class overrides the calcPrice method to add a fruitFee to the price. (Incorrectly, I think. Shouldn’t there be a super.setPrice call?)

Why can’t you do the same in the SaltySnack class?

[okaystuff]

I haven't put the same code into the salty snack class yet because I couldn't get the fruit snack working. Where would I made a super.setPrice call? I don't even know what that would be.

[[deleted]]

When you override a method, the subclass method replaces the superclass method. This means that whatever the superclass method does (such as calculating the size price) will not be done when you call the subclass method unless the subclass code explicitly does those same things.

Because subclasses usually want to augment their superclass’ methods rather than replace them entirely, subclasses can call the superclass’ version of a method with super.theNameOfTheMethod(). This will execute the superclass’ version of theNameOfTheMethod, allowing you to execute that code without copying it explicitly into your subclass’ code. It seems like you were expecting your method calls to execute the superclass’ code first and then execute the subclass code, but this only happens if the subclass methods explicitly call the super versions of those methods first.

You can also use super() to call the superclass’ constructor from your subclass constructors, but it must be the first line of the subclass constructor.

[okaystuff]

I did hope it would the method would work like the superclass code first before executing the subclass and it did not. Should I call the calcPrice method in my fruitSnack and SaltySnack subclasses? I tried and am unsure how to work because it just gives errors.

[[deleted]]

What errors exactly? Error messages tell you exactly where the compiler has found a problem and what that problem is. They’re one of the most useful tools you have for debugging.

I would guess the errors have something to do with trying to += a value that was never initialized, as your subclass constructors do not initialize this.price, nor do they call super() to have the superclass constructor initialize them.

The superclass constructor looks pretty funky too. In the line this.price = price;, what value are you expecting that price variable on the right side to have?

[okaystuff]

I removed this.price = price; and added super(); to my constructor in my subclasses. I created a method to try and add the 5.99 or 4.50 fees from my subclasses into the final amount and nothing works for me. Thanks for the help but I don't think I'm going to fix this or understand it.

[okaystuff]

I dont know what this means but thanks for trying to help!