Exercise 2.20 - Java Interest Calculator

The program below is the solution to Liang's Introduction to Java Programming (9th Edition) Chapter 2 Exercise 2.20.

Question: If you know the balance and the annual percentage interest rate, you can compute the interest on the next monthly payment using the following formula:

interest = balance * (annualInterestRate /1200)

Write a program that reads the balance and the annual percentage interest rate and displays the interest for the next month.

/**
 *
 * @Author: Aghatise Osazuwa
 * Website: www.cscprogrammingtutorials.com
 *
 * Exercise 2.20 - Financial application: calculate interest
 *
 */ 

import java.util.Scanner;

public class Ex02_20 {

    public static void main(String[] args) {
        
        //Display Program Information
        System.out.println("This Program Calculates Interest On The Next Monthly"
                + " Payment.\n");

        //create Scanner 
        Scanner input = new Scanner(System.in);

        //prompt user to enter details
        System.out.print("Enter balance and annual percentage interest rate "
                + "(e.g., 3 for 3%): ");
        double balance = input.nextDouble();
        double annualInterestRate = input.nextDouble();

        //calculate interest using the formula interest = balance * (annualInterestRate / 1200)
        double interest = balance * (annualInterestRate / 1200);
        //format interest to five decimal places
         interest = (int)(interest * 100000)/100000.0;

        //display the result
        System.out.println("The interest is " + interest + "\n");
    }
}

Program output

Click here to see other solutions to Introduction to Java Programming.