What is wrong with my loop

Question

I'm a beginner Java student trying to make this code list the amount saved and interest for 8 years. I'm trying to use a for loop for it. It calculates the interest but only lists it for 1 year. Would appreciate any help solving this problem.

import javax.swing.JOptionPane;   
import java.text.*;

public class RetirementGoal3   

{
private static DecimalFormat percentFormat = new DecimalFormat("###.##%");
private static DecimalFormat moneyFormat = new DecimalFormat("$###,###,###.00");
private static double interest;
private static double saveAmount;
private static double total;
private static int Max_Year = 8;
private static int year;
private static double totalSave;
private static double totalInterest;

public static void main(String[] args)
{
     calculateR();
}


public static double calculateR()                         
{                                   
 String result = JOptionPane.showInputDialog(null, "Enter how much money you can save annually.");
 if(result != null)
 saveAmount = Double.parseDouble(result);

 String result1 = JOptionPane.showInputDialog(null, "Enter your interest rate(As a decimal)");
 if(result1 != null) 
 interest = Double.parseDouble(result1); 


 totalSave = saveAmount;

   for(year = 1; year <= Max_Year; ++ year)
   {
    totalInterest = saveAmount + saveAmount * interest;
       JOptionPane.showMessageDialog(null, "    If you save " + moneyFormat.format(totalSave) + " each year for " + Max_Year + " years" + "\n        With " + percentFormat.format(interest) + " Interest" + "             Without Interest" + "\n\nAfter year " + year + "  " + moneyFormat.format(totalSave) + "               " + moneyFormat.format(totalInterest));

    return total;
   } 



     return total;  
   }

}

Answer 1

You have a return statement inside your for loop. So, the first iteration returns, exiting the for loop right away.

You have a return statement already in the correct location, after the for loop, so all you have to do is remove the return statement that is inside the for loop.

Answer 2

Change you loop to :

for(year = 1; year <= Max_Year; ++ year)
{
  totalInterest = saveAmount + saveAmount * interest;
   JOptionPane.showMessageDialog(null, "    If you save " + moneyFormat.format(totalSave) + " each year for " + Max_Year + " years" + "\n        With " + percentFormat.format(interest) + " Interest" + "             Without Interest" + "\n\nAfter year " + year + "  " + moneyFormat.format(totalSave) + "               " + moneyFormat.format(totalInterest));
} 

Remove the return. As soon as you do a return it stops execution of that function and return to the callers.

Answer 3

for(year = 1; year <= Max_Year; ++ year)
{
    totalInterest = saveAmount + saveAmount * interest;
    JOptionPane.showMessageDialog(null, "    If you save " + moneyFormat.format(totalSave) + " each year for " + Max_Year + " years" + "\n        With " + percentFormat.format(interest) + " Interest" + "             Without Interest" + "\n\nAfter year " + year + "  " + moneyFormat.format(totalSave) + "               " + moneyFormat.format(totalInterest));

    return total; //<-- PROBLEM

} 

The problem is the return inside the loop. It executes one iteration and when it gets to the return statement it exits the loop. I guess you want to move it outside the loop.

Update after your comment: Try this

 String resultString = "";

 for(year = 1; year <= Max_Year; year++)
 {
 totalInterest = saveAmount + saveAmount * interest;

     resultString += "    If you save " + moneyFormat.format(totalSave) + 
                     " each year for " + Max_Year + " years" + "\n" +
                     "        With " + percentFormat.format(interest) + " Interest" + 
                     "             Without Interest" + "\n\nAfter year " + year + "  " + 
                     moneyFormat.format(totalSave) + 
                     "               " + moneyFormat.format(totalInterest) + "\n";

 } 
 JOptionPane.showMessageDialog(null, resultString);

 return total;
}

Note that this will display things the way you want to but i think your calculations go wrong somewhere.