java - 格式化数字打印输出异常

Question

Exception in thread "main" java.util.InputMismatchException  
    at java.util.Scanner.throwFor(Scanner.java:864)  
at java.util.Scanner.next(Scanner.java:1485)    
at java.util.Scanner.nextInt(Scanner.java:2117)     
at java.util.Scanner.nextInt(Scanner.java:2076)     
at Commission2.main(Commission2.java:38)

一开始运行得很好，直到一切都崩溃了。现在我需要帮助。有人吗？

import java.util.Scanner;//程序需要scanner 导入java.text.DecimalFormat;

public class Commission2
{

public static void main(String args[])

    {

        //create Scanner
    Scanner input = new Scanner(System.in);

    //format decimal with two digits
    DecimalFormat twoDigits = new DecimalFormat("0.00");
    //format decimal with three digits
    DecimalFormat threeDigits = new DecimalFormat("0.000");

    //declare all variables
    int size,count = 0;
    int pay = 200;
    double commission = 9/100;
    double result = 0;
    double item, itemtotal = 0;

    //get the limit of the data entry (data validation technique)
    do{
        System.out.printf("Enter the number of items :");
            size = input.nextInt();

    }while(size < 0);

    //data entry
    while (count < size) {

        System.out.print("Enter price of item #" +(count + 1) +": ");
            item = input.nextInt();


        /*Processing!*/
        itemtotal += item;
        ++count;


    }//end while
        result = (itemtotal * commission) + pay;

    System.out.printf("%s%d\n","The total earnings for this week is $",result);




    }
}

Answer 1

在第 25 行，您声明了 double item，但在第 38 行，您尝试将 input.nextInt() 分配给变量 item。

如果您要在此处提供Integer 值 (5)，则代码应按预期工作。但是，当提供 Double 时 (5,12)，将引发 InputMismatchException 异常。

要解决此问题，只需更改此:

item = input.nextInt();

对此:

item = input.nextDouble();