Computing Taxes in Java

Problem:

Rewrite a program that compute taxes using arrays. For each filing status, there are six tax rates. Each rate is applied to a certain amount of taxable income. For example, from the taxable income of $400,000 for a single filer, $8,350 is taxed at 10%, (33,950 – 8,350) at 15%, (82,250 – 33,950) at 25%, (171,550 – 82,550) at 28%, (372,550 – 82,250) at 33%, and (400,000 – 372,950) at 36%. The six rates are the same for all filing statuses, which can be represented in the following array:

double[] rates = {0.10, 0.15, 0.25, 0.28, 0.33, 0.35};

The brackets for each rate for all the filing statuses can be represented in a two dimensional array as follows:

int[][] brackets = {
{8350, 33950, 82250, 171550, 372950}, // Single filer
{16700, 67900, 137050, 20885, 372950}, // Married jointly
{8350, 33950, 68525, 104425, 186475}, // Married separately
{11950, 45500, 117450, 190200, 372950} // Head of household
};

Suppose the taxable income is $400,000 for single filers. The tax can be computed
as follows:
tax = brackets[0][0] * rates[0] +
(brackets[0][1] – brackets[0][0]) * rates[1] +
(brackets[0][2] – brackets[0][1]) * rates[2] +
(brackets[0][3] – brackets[0][2]) * rates[3] +
(brackets[0][4] – brackets[0][3]) * rates[4] +
(400000 – brackets[0][4]) * rates[5]

Output:

How much money do you make? 10000
Enter 0 if you are single filder,
1 if you are married jointly,
2 if you are married seperately,
and 3 if you are head of household.
0
Taxes are 1082.5

Solution:

import java.util.Scanner;

public class ComputingTax
{
  public static void main (String[] args)
  {
    Scanner scan = new Scanner (System.in);
    System.out.print("How much money do you make? ");
    int salary = scan.nextInt();
    System.out.println("Enter 0 if you are single filder,");
    System.out.println("1 if you are  married jointly,");
    System.out.println("2 if you are married seperately,");
    System.out.println("and 3 if you are head of household.");
    int i = scan.nextInt();
    double tax = 0;
    int[][] brackets = {
        {8350, 33950, 82250, 171550, 372950}, // Single filer
        {16700, 67900, 137050, 20885, 372950}, // Married jointly
        {8350, 33950, 68525, 104425, 186475}, // Married separately
        {11950, 45500, 117450, 190200, 372950} // Head of household
        };
    
    double[] rates = {0.10, 0.15, 0.25, 0.28, 0.33, 0.35};
    if (salary > brackets[i][4])
    tax =   ((brackets[i][0] - 000000000000000) * rates[0]) + 
        ((brackets[i][1] - brackets[i][0]) * rates[1]) + 
        ((brackets[i][2] - brackets[i][1]) * rates[2]) + 
        ((brackets[i][3] - brackets[i][2]) * rates[3]) + 
        ((brackets[i][4] - brackets[i][3]) * rates[4])+ 
        ((salary - brackets[i][4]) * rates[5]);
    
    else if (salary > brackets[i][3])
      tax =   ((brackets[i][0] - 000000000000000) * rates[0]) + 
      ((brackets[i][1] - brackets[i][0]) * rates[1]) + 
      ((brackets[i][2] - brackets[i][1]) * rates[2]) + 
      ((brackets[i][3] - brackets[i][2]) * rates[3]) + 
      ((salary - brackets[i][3]) * rates[4]);
    
    else if (salary > brackets[i][2])
      tax =   ((brackets[i][0] - 000000000000000) * rates[0]) + 
      ((brackets[i][1] - brackets[i][0]) * rates[1]) + 
      ((brackets[i][2] - brackets[i][1]) * rates[2]) + 
      ((salary - brackets[i][2]) * rates[3]);
    
    else if (salary > brackets[i][1])
      tax =   ((brackets[i][0] - 000000000000000) * rates[0]) + 
      ((brackets[i][1] - brackets[i][0]) * rates[1]) +
      ((salary - brackets[i][1]) * rates[2]);
    
    else if (salary > brackets[i][0])
      tax =   ((brackets[i][0] - 000000000000000) * rates[0]) + 
      ((salary - brackets[i][0]) * rates[1]);

    System.out.println("Taxes are " + tax);
  }
}