Chapter 3.4, Problem 20SC

Program Plan Intro

Given Program:

The program given in the textbook is given here with comments for better understanding.

File Name: TaxReturn.java

// Class definition

public class TaxReturn

{

    // Declare and initialize the required variables

    public static final int SINGLE = 1;

    public static final int MARRIED = 2;

    private static final double RATE1 = 0.10;

    private static final double RATE2 = 0.25;

    private static final double RATE1_SINGLE_LIMIT = 32000;

private static final double RATE1_MARRIED_LIMIT = 64000;

    private double income;

    private int status;

/*Constructs a TaxReturn object for a given income and marital status.

  @param anIncome the taxpayer income

  @param aStatus either SINGLE or MARRIED */

    // Method definition

    public TaxReturn(double anIncome, int aStatus)

    {

        income = anIncome;

        status = aStatus;

    }

    // Method definition

    public double getTax()

    {

        // Declare and initialize the required variables

        double tax1 = 0;

        double tax2 = 0;

/* If the entered status is "Single", compute income tax based on their income */

        if (status == SINGLE)

        {

/* Check whether the income is less than or equal to $32000 */

            if (income <= RATE1_SINGLE_LIMIT)

            {

                // If it is, compute the tax

                tax1 = RATE1 * income;

            }

/* If the income is greater than or equal to $32000, compute the tax */

            else

            {

                tax1 = RATE1 * RATE1_SINGLE_LIMIT;

tax2 = RATE2 * (income - RATE1_SINGLE_LIMIT);

            }

        }

/* If the entered status is "Married", compute income tax based on their income */

        else

        {

/* Check whether the income is less than or equal to $64000 */

            if (income <= RATE1_MARRIED_LIMIT)

            {

                // If it is, compute the tax

                tax1 = RATE1 * income;

            }

/* If the income is greater than or equal to $64000, compute the tax */

            else

            {

                tax1 = RATE1 * RATE1_MARRIED_LIMIT;

tax2 = RATE2 * (income - RATE1_MARRIED_LIMIT);

            }

        }

        // Return the tax to the main function

        return tax1 + tax2;

    }

}

File Name: TaxCalculator.java

// Import the required package

import java.util.Scanner;

/**

This program calculates a simple tax return.

 */

// Class definition

public class TaxCalculator

{

    // Main class declaration

    public static void main(String[] args)

    {

        // Create an object for scanner class

        Scanner in = new Scanner(System.in);

        // Prompt the user to enter the income

        System.out.print("Please enter your income: ");

        // Store the entered income in the variable

        double income = in.nextDouble();

        // Prompt the user to enter marital status

        System.out.print("Are you married? (Y/N) ");

        // Store the entered value in a variable

        String input = in.next();

        // Declare the variable

        int status;

/* Check whether the user input value for marital status is "Y" */

        if (input.equals("Y"))

        {

/* If it is "Y", store the taxreturn value for a married person in the variable */

            status = TaxReturn.MARRIED;

        }

/* Check whether the user input value for marital status is "N" */

        else

        {

/* If it is "N", store the taxreturn value for a single person in the variable */

            status = TaxReturn.SINGLE;

        }

        // Create an object for TaxReturn class

TaxReturn aTaxReturn = new TaxReturn(income, status);

// Display the tax return value based on the user input

        System.out.println("Tax: "

                + aTaxReturn.getTax());

    }

}