Question

您好，我无法让我的程序正常运行。我能够清除任何语法错误，但现在我已经发出了我的输出。

首先，在第一个IF语句中，它会提示该人同时输入他们的姓名和部门，这样当输出时，名称为空，只有部门输入。我认为它与整个IF语句有关，因为如果我将“String name”更改为input.next，则名称提示正确，但dept和totalHrsWkd合并在一起。

此外，在测试我的程序时，当我输入totalHrsWkd的负数时，它会崩溃。它将在一行中显示两个打印语句，然后崩溃JCreator。

我很感激有关此事的任何帮助，谢谢！

    public static void main(String[] args)
    {
    // TODO code application logic here

    int attempt = 1, employeeID = 0;
    double hoursWorked = 0.0;
    double overtimeHrs = 0.0;
    double totalHrsWkd = 0.0;

    Scanner input = new Scanner(System.in);

    while( attempt < 4 )
    {
        System.out.println( "Enter your employee ID: " );
      employeeID = input.nextInt();

        if( employeeID == 12345678 )
        {
        System.out.printf( "Enter your name: " );
        String name = input.nextLine();

    System.out.printf( "Enter your department: " );
        String dept = input.nextLine();

    System.out.printf( "Enter your hours worked including overtime:  " );
        totalHrsWkd = input.nextDouble();

        while( totalHrsWkd < 0 )
            {
            System.out.printf( "Try again!  Hours worked cannot be negative.");

            System.out.printf( "Enter your hours worked including overtime: ");
            }

            overtimeHrs = totalHrsWkd - 40;
            hoursWorked = totalHrsWkd - overtimeHrs;

            if( overtimeHrs <= 0 )
            {
            }
            else if( overtimeHrs == 0 )
            {
            }
            else if( hoursWorked == totalHrsWkd )
            {
            }
            else if( hoursWorked == 40 )
            {
            }
        System.out.printf( "Name: %s\n" + "Dept: %s\n" + 
                    "Hours Worked:  %.2f\n" + "Overtime Hours: %.2f\n"
                     + "Total Hours Worked: %.2f\n", name, dept, 
                     hoursWorked, overtimeHrs, totalHrsWkd);

        attempt = 3;
        }
    else
    {
        if(attempt < 3)
        {
        System.out.println( "Invalid ID!  Try again."  );
        }
        else
        {
        System.out.println( "Invalid ID!  0 attempts left.  Exiting program!" );
        }

      }

    ++attempt;
   }
    System.exit(0);
}
}

Answer 1

问题在于

  employeeID = input.nextInt();

仅从输入流中读取下一个数字序列。但是，为了实际键入员工ID，您还必须按Enter键。 Enter键仍然在等待输入，所以下次调用时

    String name = input.nextLine();

Scanner课程“哦，这是一个Enter键，我想用户想要一个空名。”你甚至没有机会输入一个名字，这就是为什么你的程序似乎同时提出两个问题（名称和部门）。

如果您希望继续使用Scanner课程，我建议您避免使用nextInt()等方法，并始终使用nextLine()。当然，您必须使用类似的东西将用户键入的数字转换为Java整数 parseInt()

Answer 2

attempt = 3; // Seems suspicious

attempt++; // I think it's more appropriate in loops of this kind than ++attempt

Answer 3

当totalHrsWkd小于0时，程序无效的原因是以下代码创建了无限循环。

  while ( totalHrsWkd < 0 )
            {
            System.out.printf( "Try again!  Hours worked cannot be negative.");

            System.out.printf( "Enter your hours worked including overtime: ");
            }

您还应该阅读此循环中的工作小时数。

while循环使用嵌套的if / else语句

3 个答案: