Java Method Help

[samanthaxc]

My program is supposed to allow the user to input a principle amount and rate, which it will calculate the the balance after it has been compounded for 10 years. It should display the balance at the end of every year. My problem is that when I try to return the amount to the main method, it won't work. some please help!

Java:

import java.io.*; import java.text.*; public class compoundInterest { public static void main( String[] args ) throws IOException {      String depositA, rateA;// String variables are declared     double deposit, rate;// double variables are declared     BufferedReader myInput = new BufferedReader (new InputStreamReader (System.in));// Buffered Reader reads the number inputed by the user         System.out.println("Enter the amount of your initial deposit: ");// asks user to input deposit amount     depositA = myInput.readLine();// reads previous value entered     deposit = Double.parseDouble(depositA);// converts value into a double/decimal         System.out.println("Enter the rate in a decimal form (e.g: 5% -> 0.05): ");//asks user to input rate in decimal form     rateA = myInput.readLine();// reads previous value entered     rate = Double.parseDouble(rateA);// converts value into a double/decimal         for (int year = 1; year < 11; year++)     {      System.out.println("The balance after " + year + " year(s) is:\t" + "$" + findAmount( year ));// outputs a sentence displaying the balance after each year     } }         public static int findAmount (int finalNumA)     {       double amount = 0, amountB = 0, rate = 0, year = 0, deposit = 0;       int finalNumB;       amount = (1 + rate);// adds 1 to the decimal rate given earlier       amountB = Math.pow(amount, year);// takes amount and ploaces it to the power of 10. assigned a new variable, amountB             DecimalFormat total = new DecimalFormat("#0.00");// Assigns two decimal places to the answer       double amountC = amountB * deposit;// amountB is multiplied by the deposited amount, and is assigned a variable, amountC      String finalNum = total.format(amountC);//applies decimal place format to amountC, and is assigned a new variable, amountD       return finalNumB;     } }

Mod Edit:

Please wrap you code in either of the following in order to preserve whitespace (indentation) and to highlight the syntax.

code:

[syntax="java"] ... code ... [/syntax] [code] ... code ... [/code ]

[Zren]

Define exactly how it doesn't work. Does it show the wrong calculation? Does it not output at all? Does it cause an error? If it causes an error, what does the error message say?

[samanthaxc]

When I compile the program, it says the "return finalNumB" is incompatible and should be an 'int'

[Zren]

Well you're defining it as an int alright. However, you seem to be trying to return a value that hasn't been initialized (you don't set it to anything).

You're probably going to run into all the years showing the same result. For this, I suggest you take a closer look at what variables you're using for what (and which you're not using at all).

You also seem to be trying to format the value into a string inside that function that will be returning an integer. I suggest you make two functions, one to format the number into a humanly readable money string, and another to do your logic.
Eg:

Java:

formatMoney(compoundInterest(deposit, rate, numIterations))

[ishidon]

I believe what you're looking for is

code:

import java.io.*; public class compoundInterest {     public static void main( String[] args ) throws IOException {         String depositA, rateA;// String variables are declared         double deposit, rate;// double variables are declared         BufferedReader myInput = new BufferedReader (new InputStreamReader (System.in));// Buffered Reader reads the number inputed by the user                 System.out.println("Enter the amount of your initial deposit: ");// asks user to input deposit amount         depositA = myInput.readLine();// reads previous value entered         deposit = Double.parseDouble(depositA);// converts value into a double/decimal                 System.out.println("Enter the rate in a decimal form (e.g: 5% -> 0.05): ");//asks user to input rate in decimal form         rateA = myInput.readLine();// reads previous value entered         rate = Double.parseDouble(rateA);// converts value into a double/decimal                 double num;         for (int year = 1; year <= 10; year++) {             num = cInterest(deposit, rate, year);             System.out.printf("The balance after %d year(s) is: $%.2f\n", year, num);// outputs a sentence displaying the balance after each year         }     }         public static double cInterest(double principal, double interest, int year) {         return (principal*Math.pow((1+interest),year));     } }