java - Java中的复利计画

我试图在最后用do while循环编写此复利程序，但我不知道如何打印最终金额。

这是我到目前为止的代码：

public static void main(String[] args) {
    double amount;
    double rate;
    double year;

    System.out.println("This program, with user input, computes interest.\n" +
    "It allows for multiple computations.\n" +
    "User will input initial cost, interest rate and number of years.");

    Scanner keyboard = new Scanner(System.in);

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

    System.out.println("What is the interest rate?");
    rate = keyboard.nextDouble();
    rate = rate/100;

    System.out.println("How many years?");
    year = keyboard.nextInt();


    for (int x = 1; x < year; x++){
        amount = amount * Math.pow(1.0 + rate, year);
                }
    System.out.println("For " + year + " years an initial " + amount + " cost compounded at a rate of " + rate + " will grow to " + amount);


    String go = "n";
    do{
        System.out.println("Continue Y/N");
        go = keyboard.nextLine();
    }while (go.equals("Y") || go.equals("y"));
}

}

最佳答案

问题是amount = amount * Math.pow(1.0 + rate, year);。您正在用计算出的金额覆盖原始金额。您需要一个单独的值来保存计算所得的值，同时仍保留原始值。

所以：

double finalAmount = amount * Math.pow(1.0 + rate, year);

然后在您的输出中：

System.out.println("For " + year + " years an initial " + amount +
    " cost compounded at a rate of " + rate + " will grow to " + finalAmount);

编辑：或者，您可以保存一行，一个变量，然后直接进行内联计算，如下所示：

System.out.println("For " + year + " years an initial " + amount +
    " cost compounded at a rate of " + rate + " will grow to " +
    (amount * Math.pow(1.0 + rate, year)));