Question

Create a Java Program to calculate compound interest.

This can all be done in the main() method.

1. Create a double variable named currentBalance.
2. Create a double variable named newBalance.
3. Create a final double variable named INTEREST_RATE and assign 1.05 to it.
4. Create a int variable named yearCount.
5. Prompt for the "Number of years to invest" and store the input into the yearCount variable.
6. Prompt for the "Amount to Invest" and store this in the currentBalance variable.
7. Assign currentBalance to newBalance.
8. Using a 'FOR' loop, create and display the balance for each year. Additional variables may be required ( such as for the current year being displayed)
   1. newBalance= newBalance * INTEREST_RATE;
   2. Review the FOR loop example in Chapter 6 -Section 6.3 page 92
   3. Format the displayed balance to show 2 decimal places only.

Example:

Number of years to invest:5

Amount to Invest:1000

Year 1 balance =  1050.00
Year 2 balance =  1102.50
Year 3 balance =  1157.63
Year 4 balance =  1215.51
Year 5 balance =  1276.28


   Display the message "You have doubled your investment" and terminate the loop if/when you have more than doubled your initial investment.

Answer 1

Answer:

I have written the below Java program based on your requirements.

The below code has no-error and it is working perfectly.

I have also attached the Output Screenshot that I got by running the below program.

Just save the below Java file as Main.java and then Compile & run.

***********************************************************************************************************

Output:

*********************************************************************************************************************

Code:

Main.java

import java.io.*;
import java.util.*;

public class Main
{
   public static void main(String[] args)
   {
       Scanner sc=new Scanner(System.in);
      
       double currentBalance, newBalance;
       final double INTEREST_RATE=1.05;
       int yearCount;
      
       System.out.print("\nNumber of years to invest:");
       yearCount=sc.nextInt();
      
       System.out.print("Amount to Invest:");
       currentBalance=sc.nextDouble();
      
       newBalance=currentBalance;
      
       System.out.println();
      
       for(int i=1;i<=yearCount;i++)
       {
           newBalance=newBalance*INTEREST_RATE;
           if(newBalance>=currentBalance*2)
           {
               System.out.println("You have doubled your investment");
               break;
           }
           System.out.println("Year "+i+" balance = "+String.format("%.2f", newBalance));
       }
   }
}