Step 4

import java.text.NumberFormat;
import java.util.Scanner;



public class InvoiceApp

{

    public static void main(String[] args)

    {

                Scanner sc = new Scanner(System.in);

                String choice = "y";



                while (!choice.equalsIgnoreCase("n"))


                {

                    // get the input from the user

                    System.out.print("Enter customer type (r/c/t): ");

                    String customerType = sc.next();


                    System.out.print("Enter subtotal:   ");

                    double subtotal = sc.nextDouble();



                    // get the discount percent

                    double discountPercent = 0;

                    if (customerType.equalsIgnoreCase("R"))

                    {

                        if (subtotal < 100)

                            discountPercent = 0;

                        else if (subtotal >= 100 && subtotal < 250)

                            discountPercent = .1;

                        else if (subtotal >= 250 && subtotal <500)

                            discountPercent = .25;

                        else if (subtotal >= 500)

                            discountPercent = .3;

                    }

                    else if (customerType.equalsIgnoreCase("C"))

                    {

                            discountPercent = .2;

                    }

                    else if (customerType.equalsIgnoreCase("T"))

                    {
                                if (subtotal <500){
                                        discountPercent = .4;
                                }
                                else{
                                        discountPercent = .5;
                                }


                    }

                    else{

                        System.out.println("That is not a valid customer type.");

                    }



                    // calculate the discount amount and total

                    double discountAmount = subtotal * discountPercent;

                    double total = subtotal - discountAmount;



                    // format and display the results

                    NumberFormat currency = NumberFormat.getCurrencyInstance();

                    NumberFormat percent = NumberFormat.getPercentInstance();


                    System.out.println(

                        "Discount percent: " + percent.format(discountPercent) + "\n" +

                        "Discount amount:  " + currency.format(discountAmount) + "\n" +

                        "Total:            " + currency.format(total) + "\n");



                    // see if the user wants to continue

                    System.out.print("Continue? (y/n): ");

                    choice = sc.next();

                    System.out.println();

                }

    }

}