如何在另一方法的方程式中的一种方法中使用变量？

Question

So, I'm doing this project for school, and I have a feeling it's really simple, but that I'm just really dumb. I need to have two methods; one that only does the calculations I want done, and another where the user enters in numbers and displays the answers from the calculations method. The sample from the class website makes it easy to understand how to use one user-entered variable, but not 3 like I need; I also need to be able to multiply them all together and use them in an equation. Here's what I have so far:

import java.util.*;
import java.text.*;

public class Lab3StarterCodeExperimental {
  public static final Scanner CONSOLE = new Scanner(System.in);

  public static double compoundInterest(double accountValue) {
    double firstCalc = accountValue * 150;
    return firstCalc;
  }


  public static void main(String [] args) {
    //print title of lab
    System.out.println("Lab 3");

    //get user input (present value of account, interest rate, # years, payment per year)
    System.out.print("Enter present value of the account: ");
    double presentValue = CONSOLE.nextDouble();
    System.out.print("Enter the interest rate of the account: ");
    double interestRate = CONSOLE.nextDouble();
    System.out.print("Enter the number of years: ");
    double numOfYears = CONSOLE.nextDouble();

    //calculate future value of account
    double fvAccount = compoundInterest(presentValue);

    //calculate future value of annuity

    //print everything
    System.out.println("Fake Variable is " + presentValue);
    System.out.println("Future value of account is " + fvAccount);
  }
}

Any help is greatly appreciated!

Answer 1

public double getWhateverResult(double presentValue, double interestRate, double numOfYears)  {
   double doubleResult = //do stuff
   return  doubleResult;
}

Call it with

double doubleResult = getWhateverResult(presentValue, interestRate, numOfYears);
System.out.println(doubleResult);