java - 在我的程序中使用 for 循环时出现问题

Question

在我的代码中，我让用户输入 3 个内容，对于第三个输入，我要求输入年数。但是，在我的 for 循环中，我无法使用要求用户输入的变量。例如，如果用户输入“3”，我的代码将执行15年(这是最大值)。

double yearInvest;
double interRate;
double numOfYears = 3;
double amountBeforeTotal;
double amountTotal;
double years;

System.out.println("Compound Interest \n");
System.out.println("This program will print out a title table that will "
    + " display the amount of a yearly investment over a period of "
    + " up to 15 years. \n");

Scanner input = new Scanner(System.in);
System.out.println("Enter the yearly investment:");
yearInvest = input.nextDouble();
System.out.println("Enter the interest rate (%):");
interRate = input.nextDouble();
System.out.println("Enter the number of years:");
numOfYears = input.nextDouble();

for (years = 1; 15 >= years; years++) {
    System.out.format("%-4s %22s %12s %8s \n ", "Year", "Amount in Account",
        "Interest", "Total");

    amountTotal = (yearInvest * (interRate / 100)) + yearInvest;
    System.out.format("%-4.1f", years);
    System.out.format("%18.2f", yearInvest);
    System.out.format("%14.2f", interRate);
    System.out.format("%15.2f", amountTotal);
}

附注我仍在编写代码，尚未完全完成。如果可能的话，我也希望得到一些建议。

Answer 1

System.out.println("Enter the number of years:");
numOfYears = input.nextDouble();

for (years = 1; 15 >= years; years++) 

您的代码正在获取用户输入的numOfyears，对于您的情况，例如为 3。无论如何，你的循环都是从 (1..15) 开始的，因为你的循环的第二个参数是:15 >= 年。

您要查找的是 (1..numOfYears)

System.out.println("Enter the number of years:");
numOfYears = input.nextDouble();

for (years = 1; years <= numOfYears; years++) 
    //...more code