Thread: Catch without a try error

I'm doing a project where I have to catch a user inputting a string into one of the prompt.
Problem is it seems I always get catch without a try error no matter what I do.
it keeps saying expected ";" on the catch statement... which is incorrect.
error(s) are appearing at line 49 - try without a catch.
Line 102 - catch without a try.
line 92 - while statement is unreachable.
and line 107 which is a bracket it says " class, or enum expected".
I couldn't tell you what I did fix because my original code was something completely different so I restarted a few things to fix certain problems that could occur.
I've looked around the internet found bad examples to try to fix my code with myself.

//This is a program that will calculate a monthly payment and loop it. If user gives bad data you will be prompted.
 
package monthypayment2;
import java.text.NumberFormat;
import java.util.Scanner;
 
 
public class Monthypayment2 {
    private static double monthlypay1;
    private static String choice;
    private static boolean n;
    private static String False;
    private static boolean y;
 
 
 
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
 
        //format number and currency
       NumberFormat NF = NumberFormat.getCurrencyInstance();
 
 
        double months;
        double numyears;
        double loanamount;
        double rate;
        double monthlypay1;
        String choice = "y";
        double calc1;
        double calc2;
        double calc3;
        double calc4;
 
 
 
 
      while (choice.equals("y")) {
 
try {
        //prompt loan amount
        loanamount=0;
        rate = 0;
        numyears = 0;
 
 
        System.out.print("Enter Loan Amount:");                           
        loanamount = Double.parseDouble(in.nextLine());
 
        //prompt rate
        System.out.print("Enter Rate:");
         rate = Double.parseDouble(in.nextLine());
 
 
         //prompt years
        System.out.print("Enter Number of Years:");
        numyears = Double.parseDouble(in.nextLine());
 
        rate = rate / 12 / 100;
        months = 12 * numyears;
 
 
      //calculation monthly
        calc1 = loanamount * rate;
        calc2 = (Math.pow (1 + rate, months));
        calc3 = (calc2 -1);
        calc4 = (calc2 / calc3);
 
        monthlypay1 = loanamount * rate * calc4;
 
 
 
         if ((loanamount > 0 && rate > 0) && numyears > 0 ) {
            System.out.println("The Monthly Payment is:" + NF.format (monthlypay1));  
            } else { 
             System.out.println("You need to enter positive numerical data!");
 
         }
            break;
 
}
 
        while (monthlypay1 < 0) {
            System.out.print("You need to enter positive numerical data!");
            break;
 
 
         }
            System.out.print("");
            System.out.print("Would you like to continue calculations( y / n)?");
 
            choice  = in.nextLine();
 
 
           catch (Exception e) {
               }
       }
    }
}

Thanks alot guys. I will look at the tutorial. And My java teacher told me to put everything within the try block to make it more simple. Because it will try through everything and catch any error at the end.

Ok i fixed the error's of catch without a try and vice versa. But now its telling me that my variable "monthlypay1" is not initialized which I don't understand how it isn't. Otherwise the code wouldn't work at the beginning...
The error is occurring at the last while statement.

package monthypayment2;
import java.text.NumberFormat;
import java.util.Scanner;
 
 
public class Monthypayment2 {
    private static double monthlypay1;
    private static String choice;
    private static boolean n;
    private static String False;
    private static boolean y;
 
 
 
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
 
        //format number and currency
       NumberFormat NF = NumberFormat.getCurrencyInstance();
 
 
        double months;
        double numyears;
        double loanamount;
        double rate;
        double monthlypay1;
        String choice = "y";
        double calc1;
        double calc2;
        double calc3;
        double calc4;
 
 
 
 
      while (choice.equals("y")) {
 
 try {
        //prompt loan amount
        loanamount=0;
        rate = 0;
        numyears = 0;
 
 
        System.out.print("Enter Loan Amount:");                           
        loanamount = Double.parseDouble(in.nextLine());
 
        //prompt rate
        System.out.print("Enter Rate:");
         rate = Double.parseDouble(in.nextLine());
 
 
         //prompt years
        System.out.print("Enter Number of Years:");
        numyears = Double.parseDouble(in.nextLine());
 
        rate = rate / 12 / 100;
        months = 12 * numyears;
 
 
      //calculation monthly
        calc1 = loanamount * rate;
        calc2 = (Math.pow (1 + rate, months));
        calc3 = (calc2 -1);
        calc4 = (calc2 / calc3);
 
        monthlypay1 = loanamount * rate * calc4;
 
 
 
         if ((loanamount > 0 && rate > 0) && numyears > 0 ) {
            System.out.println("The Monthly Payment is:" + NF.format (monthlypay1));  
            } else { 
             System.out.println("You need to enter positive numerical data!");
 
         }
            break;
 
       } catch (Exception e ) {
       }
 
       [B] while (monthlypay1 < 0) [/B]{
            System.out.print("You need to enter positive numerical data!");
            break;
 
 
         }
            System.out.print("");
            System.out.print("Would you like to continue calculations( y / n)?");
 
            choice  = in.nextLine();
 
 
    }
}
}

The one at the bottom.

while (monthlypay1 < 0) {
            System.out.print("You need to enter positive numerical data!");
            break;
 
 
         }
            System.out.print("");
            System.out.print("Would you like to continue calculations( y / n)?");
 
            choice  = in.nextLine();

So that little bit. I can't seem to find what's wrong with it. I've tried just retyping it cause sometimes I make errors via the name.
I can't move it obviously because of how the loop works.

Thanks guys I fixed it in class today. I had to set my double monthlypay1=0; and that made it work. As for the hiding my variable's I'll fix that up so my variables aren't hiding. But thanks for everything.
topic solved. and program works.