不知道为什么我的代码会出现“非法格式转换异常”错误？

Question

我很确定错误是由最后一行引起的。从我所知，它不满意我使用变量“%d”。但这不是整数的有效输入吗？

import java.util.Scanner;

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

        int TVs;
        int VCRs;
        int controller;
        int CD;
        int recorder;
        double TV_price;
        double VCR_price;
        double controller_price;
        double CD_price;
        double recorder_price;
        double tax;
        {
            TV_price = 400.00;
            VCR_price = 220.00;
            controller_price = 35.20;
            CD_price = 300.00;
            recorder_price = 150.00;
            tax = .0825;

            Scanner in = new Scanner(System.in);
            {
                System.out.printf("How many TV's were sold? ");
                TVs = in.nextInt();

                System.out.printf("How many VCR's were sold? ");
                VCRs = in.nextInt();

                System.out.printf("How many remote controller's were sold? ");
                controller = in.nextInt();

                System.out.printf("How many CD players were sold? ");
                CD = in.nextInt();

                System.out.printf("How many Tape Recorder's were sold? ");
                recorder = in.nextInt();

                System.out.printf("QTY\tDESCRIPTION\tUNIT PRICE\tTOTAL PRICE\n");
                System.out.printf("%d", TVs + "\tTelevision\t%f", TV_price
                        + "\t" + tax * TV_price + "%f", TV_price);
            }
        }
    }
}

错误消息：

Exception in thread "main" java.util.IllegalFormatConversionException: d != java.lang.String
    at java.util.Formatter$FormatSpecifier.failConversion(Formatter.java:4011)
    at java.util.Formatter$FormatSpecifier.printInteger(Formatter.java:2725)
    at java.util.Formatter$FormatSpecifier.print(Formatter.java:2677)
    at java.util.Formatter.format(Formatter.java:2449)
    at java.util.Formatter.format(Formatter.java:2383)
    at java.lang.String.format(String.java:2781)
    at total_cost.main(total_cost.java:37)

Answer 1

由于这一行，您将获得此异常：

System.out。printf（“%d”，TVs“\tLevision\t%f”，TV_price“\t”tax*TV_ price“%f”，TV_price）

由于< code> ，因此< code > TVs " \电视\t%f"正在尝试进行算术运算。

您应该格式化输出，然后提供值。

例如：＜code＞System.out。printf（“%d%s”，TVs，“\tTelevision\”

Answer 2

您应该决定是使用< code>printf()还是< code>println()，哪一个似乎更适合您:

System.out.println(3 + "\tTelevision\t" + TV_price + "\t" + tax * TV_price + " " + TV_price);

使用＜code＞printf（）

System.out.printf("%d number %s string\n", 3, "hi");

Answer 3

您传递的是一个字符串，而不是一个整数。应该是这样的:

System.out.printf("%d\tTelevision\t%.2f\t%.2f,%.2f", TVs, TV_price,tax * TV_price, TV_price);

PS：我可以自由地用2位小数位来格式化价格。