using only import java.util.scanner;

Separating calculations into methods simplifies modifying and expanding programs.

The following program calculates the tax rate and tax to pay, using methods. One method returns a tax rate based on an annual salary.

Run the program below with annual salaries of 40000, 60000, and 0.

Change the program to use a method to input the annual salary.

Run the program again with the same annual salaries as above. Are results the same?

import java.util.Scanner;

public class IncomeTax { // Method to get a value from one table based on a range in the other table public static double getCorrespondingTableValue(int search, int [] baseTable, double [] valueTable) { int baseTableLength = baseTable.length; double value = 0.0; int i = 0; boolean keepLooking = true;

i = 0; while ((i < baseTableLength) && keepLooking) { if (search <= baseTable[i]) { value = valueTable[i]; keepLooking = false; } else { ++i; } }

return value; } public static void main (String [] args) { Scanner scnr = new Scanner(System.in); int annualSalary = 0; double taxRate = 0.0; int taxToPay = 0; int i = 0;

int [] salaryBase = { 20000, 50000, 100000, 999999999 }; double [] taxBase = { .10, .20, .30, .40 }; // FIXME: Change the input to come from a method System.out.println(" Enter annual salary (0 to exit): "); annualSalary = scnr.nextInt();

while (annualSalary > 0) { taxRate = getCorrespondingTableValue(annualSalary, salaryBase, taxBase);

taxToPay= (int)(annualSalary * taxRate); // Truncate tax to an integer amount System.out.println("Annual salary: " + annualSalary + "\tTax rate: " + taxRate + "\tTax to pay: " + taxToPay);

// Get the next annual salary // FIXME: Change the input to come from a method System.out.println(" Enter annual salary (0 to exit): "); annualSalary = scnr.nextInt(); }

return; } }