Question

Using Java

Create two exception classes to capture the improper entering of coin names and their corresponding values. Name one class CoinNameException and the other CoinValueException

Design and write a program that asks a young child to input a set of coin names and their corresponding values (in cents) in their piggybank. The program should work in a loop:

1. First, the program should prompt the child to enter the name of a coin (penny, nickel, dime, quarter, or half-dollar).
   • If an improper name for a coin is entered, then catch a CoinNameException exception, print an error message, and give the child a second chance to reenter it.
   • After two chances, terminate the program.
2. Once a valid coin name has been entered in step #1 above, the child must then enter the corresponding value of that coin in cents (1, 5, 10, 25, or 50).
   • Use either the parseInt() or the nextInt() method to get the value of the coin.
     • Hint: What exceptions can these methods throw?
   • If the child enters the wrong value for the coin, then catch a CoinValueException exception, print an error message, and give the child a second chance to reenter the value of the coin.
   • After two chances, terminate the program.
3. If a valid coin and its corresponding value are entered, add that coin to the child’s piggybank total and go back to step #1
4. Other than entering an invalid coin name or value twice, provide a nicer and simpler way for the child to exit the loop above (steps 1 – 3)
5. When the child is finished entering coins (or the program terminates), display a nicely-formatted report showing the name, value, and quantity of each coin in the child’s piggybank, along with the total value of all coins.

All exception classes should have at least two constructors:

• one which takes no arguments and provides a default Exception message
• another which takes a String as an argument and sets the contents of the String as the Exception message

Answer 1

Thanks for the question.

Below is the code you will be needing  Let me know if you have any doubts or if you need anything to change.

Thank You !!
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public class CoinValueException extends  Exception{

    public CoinValueException(String message) {
        super(message);
    }
}

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public class CoinNameException extends Exception {

    public CoinNameException(String message) {
        super(message);
    }

}

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import java.util.Scanner;

public class PiggyBank {


    private static Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) {

        int[] coins = new int[5];
        String name = "";
        int count = 0;
        while (true) {


            for (int attempts = 1; attempts <= 2; attempts++) {
                try {
                    name = getCoinName();
                    break;
                } catch (CoinNameException e) {
                    System.out.println(e.getMessage());
                    if (attempts == 2) {
                        System.out.println("Max attempts reached.\nPiggy Bank will close now.");
                        System.exit(1);
                    }
                }
            }

            for (int attempts = 1; attempts <= 2; attempts++) {
                try {
                    count = getCoinValue();
                    break;
                } catch (CoinValueException e) {
                    System.out.println(e.getMessage());
                    if (attempts == 2) {
                        System.out.println("Max attempts reached.\nPiggy Bank will close now.");
                        System.exit(1);
                    }
                }
            }
            if (name.equalsIgnoreCase("penny")) coins[0]+=count;
            else if (name.equalsIgnoreCase("nickel")) coins[1]+=count;
            else if (name.equalsIgnoreCase("dime")) coins[2]+=count;
            else if (name.equalsIgnoreCase("quarter")) coins[3]+=count;
            else if (name.equalsIgnoreCase("half-dollar")) coins[4]+=count;

            System.out.print("Do you want to add another coin: (yes/no)? ");
            String again = scanner.nextLine();
            if (again.equalsIgnoreCase("no")) break;
        }

        printCollections(coins);

    }

    private static void printCollections(int[] coins) {

        System.out.println("Piggy Bank Collection");
        System.out.println("=====================\n");
        System.out.println("Pennies     : " + coins[0]);
        System.out.println("Nickel      : " + coins[1]);
        System.out.println("Dime        : " + coins[2]);
        System.out.println("Quarter     : " + coins[3]);
        System.out.println("Half-Dollar : " + coins[4]);

        double amount = coins[0] * 0.01 + coins[1] * .05 + coins[2] * .10 + coins[3] * .25 + coins[4] * .5;
        System.out.println("Total Amount: $" + amount);

    }

    private static int getCoinValue() throws CoinValueException {

        System.out.print("Enter the number of coins: ");
        try {
            int count = scanner.nextInt();
            scanner.nextLine();
            if (count < 0) throw new CoinValueException("ERROR: Count is in negative.");
            else return count;
        } catch (NumberFormatException e) {
            throw new CoinValueException("ERROR: Input is not a number.");
        }

    }


    private static String getCoinName() throws CoinNameException {

        System.out.print("Enter coin name [penny,nickel,dime,quarter,half-dollar]: ");
        String name = scanner.nextLine();
        if (name.equalsIgnoreCase("penny") ||
                name.equalsIgnoreCase("nickel") ||
                name.equalsIgnoreCase("dime") ||
                name.equalsIgnoreCase("quarter") ||
                name.equalsIgnoreCase("half-dollar")) {
            return name.toLowerCase();
        } else {
            throw new CoinNameException("ERROR: Invalid coin name: " + name + " entered.");
        }

    }


}

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