Question

我正在尝试将一系列计算格式化为表格。到目前为止，我已经得到了字符串数据类型，但双数据类型似乎表现不同。运行程序时，我收到格式转换错误。我是java的新手，非常感谢任何帮助。我试图让它看起来像这样：

RATE    YEAR    AMOUNT ON DEPOSIT   INTEREST
----    ----    -----------------   --------
0.07     1        1,070.00          70.00
         2        1,144.90          144.90
         3        1,225.04          225.04
         4        1,310.80          310.80
         5        1,402.55          402.55
         6        1,500.73          500.73
         7        1,605.78          605.78
         8        1,718.19          718.19
         9        1,838.46          838.46
         10       1,967.15          967.15

这是我的代码:(我知道循环是关闭的，如果它看起来像上面那样。我只是想弄清楚如何格式化双打。）

import java.text.DecimalFormat;
public class interest
{
    public static void main(String[] args)
    {
        DecimalFormat money = new DecimalFormat("$#,##0.00");
        DecimalFormat percent = new DecimalFormat("0.00");
        double interest = 0;
        double principal = 1000;
        double rate7 = 0.07;
        double rate8 = 0.08;
        double rate9 = 0.09;
        double rate10 = 0.10;
        double endYear = 0;
        int yearCount = 1;
        System.out.printf("%1s%7s%20s%10s", "Rate", "Year", "Amount on Deposit" , "Interest");
        System.out.println();
        System.out.printf("%1s%7s%20s%10s", "----", "----", "-----------------", "--------");
        System.out.println();
        boolean firstTime =true;
        while (yearCount <= 10)
        {
            if(firstTime)
            {  //the issue is here
                System.out.printf("1f%7d%20f%10f", "percent.format(rate7)", "yearCount","endYear", "interest");
                firstTime = false;
            }
            else
            {
                endYear = principal * Math.pow((1 + rate7),yearCount);
                System.out.println(money.format(endYear));
                yearCount++;
                interest = endYear - 1000;
                System.out.println();
            }
        }
        System.out.format("%1s%7s%20s%10s", "Rate", "Year", "Amount on Deposit" , "Interest");
        System.out.println();
        System.out.format("%1s%7s%20s%10s", "----", "----", "-----------------", "--------");
        System.out.println();
        yearCount = 1;
        endYear = 0;
        interest = 0;
        firstTime = true;
        while (yearCount <= 10)
        {
            if(firstTime)
            {
                System.out.println(percent.format(rate8));
                firstTime = false;
            }
            else
            {
                endYear = principal * Math.pow((1 + rate8),yearCount);
                yearCount++;
                interest = endYear - 1000;
                System.out.println(money.format(endYear));
            }
        }
        System.out.format("%1s%7s%20s%10s", "Rate", "Year", "Amount on Deposit" , "Interest");
        System.out.println();
        System.out.format("%1s%7s%20s%10s", "----", "----", "-----------------", "--------");
        System.out.println();
        yearCount = 1;
        endYear = 0;
        interest = 0;
        firstTime = true;
        while (yearCount <= 10)
        {
            if(firstTime)
            {
                System.out.println(percent.format(rate9));
                firstTime = false;
            }
            else
            {
                endYear = principal * Math.pow((1 + rate9),yearCount);
                yearCount++;
                interest = endYear - 1000;
                System.out.println(money.format(endYear));
                System.out.println();
            }
        }
        System.out.format("%1s%7s%20s%10s", "Rate", "Year", "Amount on Deposit" , "Interest");
        System.out.println();
        System.out.format("%1s%7s%20s%10s", "----", "----", "-----------------", "--------");
        System.out.println();
        yearCount = 1;
        endYear = 0;
        interest = 0;
        firstTime = true;
        while (yearCount <= 10)
        {
            if(firstTime)
            {
                System.out.println(percent.format(rate10));
                firstTime = false;
            }
            else
            {
                endYear = principal * Math.pow((1 + rate10),yearCount);
                yearCount++;
                interest = endYear - 1000;
                System.out.println(money.format(endYear));
                System.out.println();
            }

        }
    }
}

Answer 1

替换

    System.out.format("%1s%7s%20s%10s", "Rate", "Year", "Amount on Deposit" , "Interest");

与

    System.out.printf("%s %7d %20f %10f", percent.format(rate7), yearCount, endYear, interest);

当你传递字符串而不是数字时。此外，对于第一个字符串元素，您没有指定'％s'。一旦你替换它，你的代码将正常工作

尝试使用java中的system.out.printf格式化双数据类型

1 个答案: