java我是否正确使用了参数？

Question

所以我是一个初学者，你可能知道，我目前正在尝试理解参数，想知道我是否做得对。这个程序可以运行，但我不想把它格式化成错误的格式，或者因为参数（？）不要改变。我们目前正在研究参数，所以我想我应该试一试，并尝试将其纳入本作业

    import java.util.Scanner;

    public class Investments
    {
        public static void main(String []args)
    {

        double investment,interestRate, futureValue;

        Scanner keyboard = new Scanner(System.in);

        System.out.println("What is the investment amount?");
        investment = keyboard.nextDouble();

        System.out.println("What is the interest rate?");
        interestRate=keyboard.nextDouble();

        futureValue = investment * (Math.pow(1+interestRate, 5));
        futureValue = investments(futureValue);
        System.out.println("Your investment afer 5 years:" + futureValue);

        futureValue = investment * (Math.pow(1+interestRate, 10));
        futureValue = investments(futureValue);
        System.out.println("Your investment after 10 years:" + futureValue);

        futureValue = investment * (Math.pow(1+interestRate, 20));
        futureValue = investments(futureValue);
        System.out.println("Your investment after 20 years:" + futureValue);

    }

    public static double investments (double futureValue)
    {
        double result;

        result = Math.round(futureValue * 100);
        result = result/100;
        return result;
    }
}

Answer 1

看起来不错！如果你想让你的投资功能更加强大，你可以把所有的逻辑都放到这里，只需输入投资、利率和投资周期

public static double investments (double investment, double interestRate, int numYears) 

那么您的主要功能可以是：

futureValue = investments(interestRate, 5); 
System.out.println("Your investment after 5 years:" + futureValue);

futureValue = investments(interestRate, 10); 
System.out.println("Your investment after 10 years:" + futureValue);

（等）