java - Java投资代码

我有一个项目，我必须编写一个程序来提示用户输入初始投资金额和目标投资金额，并计算从固定金额的初始金额增长到目标金额需要多少年（即：5％）。 （使用WHILE循环）。打印出每年的结果。例如，如果您选择投资$ 1,000 5年：
    1 1005年
    2年级1011
   等等：

我可以编译Java程序，但是只能以5％的利率提示用户进行初始投资和目标投资。输出错误。我做错了什么？这是我的代码。

import static java.lang.System.out;
import java.util.Scanner;
import java.io.*;

public class Investment_Calculator {//main
public static void main(String[] args) {//begins body

double principal = 1;//initial amount investing
double interest = 1;
double rate = 0.05;//the fixed interest amount
int years = 1;//amout of years it will take to achieve goal
double goal = 1;
double total = 1;

Scanner myScanner = new Scanner(System.in);

System.out.println("*************************************** ");
System.out.println("* Welcome to the Investment Calculator * ");
System.out.println("*************************************** ");

System.out.println ("Enter your initial investment amount: if you want to exit enter   0.");
int inputNumber = myScanner.nextInt();
principal = inputNumber;

if (inputNumber == 0){//if num = 0 exit class

System.exit(0);
}

System.out.println ("Enter your goal investment amount: ");
int inputNumber2 = myScanner.nextInt ();
goal = inputNumber2;

System.out.println ("The fixed interest rate is 5%");

total= principal; // start with our initial amount of money
for (; total < goal; total= (1+interest)*total);

{   System.out.print("The number of years you must invest to meet your goal of $ ");
 System.out.print(goal);
 System.out.print(" is");
 System.out.println(years);
 System.out.println(" years");

}
}

}

最佳答案

for (; total < goal; total= (1+interest)*total);

在此循环结束时，您将使用分号。去掉它。

因此，for循环之后的下一组print语句将成为unnamed block：-

{
 System.out.print("The number of years you must invest to meet your goal of $ ");
 System.out.print(goal);
 System.out.print(" is");
 System.out.println(years);
 System.out.println(" years");

    years++;  <-- // Increment `years` here.
}

这些将只执行一次。



更新：-

您可以使用以下代码获取每年的totalInterest以及最终输出

int years = 1;
while (principal <= goal) {
    double totalInterest = principal * rate * years / 100.0;
    principal = principal + totalInterest;

    System.out.println("Interest amount for year: " + years +
                       " = " + totalInterest);

    years++;
}

System.out.print("The number of years you must invest to meet your goal of $ ");
System.out.print(goal);
System.out.print(" is");
System.out.println(years);
System.out.println(" years");