基本 Java 问题

Question

我已经编译没有错误，但是我可以完成第一个循环没有问题。但是第二次绕过它会提示输入部门名称，但会提示输入员工人数。所以我最终看到输入部门名称：输入员工人数：

不知道为什么会发生这种情况，但我在查看时没有发现任何不合适的地方。

如果你看到我哪里出错了，你能指出行号或代码字符串吗？

谢谢。

import java.util.Scanner;

public class PayRoll {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        String name;
        int employees;
        double salary;        

        while(true) {
            System.out.print("Enter Division Name: ");
            name = input.nextLine();

            if(name.equalsIgnoreCase("stop")) {
                break;
            }else {
                System.out.print("Enter Number of Employees: ");
                employees = input.nextInt();

                while(employees <= 0) {
                    System.out.print("Number of Employees Must be Greater than 0, Please Re-enter: ");
                    employees = input.nextInt();                
                }

                System.out.print("Enter Average Salary: ");
                salary = input.nextDouble();

                 while(salary <= 0) {
                    System.out.print("Average Salary Must be Greater than 0, Please Re-enter: ");
                    salary = input.nextDouble();
                }

                Division d = new Division(name,employees,salary);
                System.out.println();
                System.out.println("Division " + d.getName());
                System.out.println("Has " + d.getEmployees() + " Employees.");
                System.out.printf("Averaging $%.2f\n",d.getSalary(),"per Employee");
                System.out.printf("Making the Division total: $%.2f\n", d.getTotal());
                System.out.println();
            }                    
        }
    }
}

class Division {
    private String name;  
    private int employees;
    private double salary;              

    public Division(String name, int employees, double salary) {
        this.name = name;
        this.employees = employees;
        this.salary = salary;
    }

    public double getTotal() {
       return employees*salary;
   }

   public String getName() {
       return name;
   }

   public void setName(String name) {
       this.name = name;
   }

   public int getEmployees() {
      return employees;
   }

   public void setEmployees(int employees) {
       this.employees = employees;
   }

   public double getSalary() {
       return salary;
   }

   public void setSalary(double salary) {
       this.salary = salary;
   }
}

Answer 1

while(true) {
    input = new Scanner(System.in);
 }

在 while 循环中实例化您的 Scanner 实例 input。

Answer 2

只需在每个 input.nextInt(); 或 输入后添加 input.nextLine();。 nextDouble(); AS：

while(true) {
    System.out.print("Enter Division Name: ");
    name = input.nextLine();
    if(name.equalsIgnoreCase("stop")) {
         break;
    }else {
         System.out.print("Enter Number of Employees: ");
         employees = input.nextInt();
         input.nextLine();  // Add it Here

        while(employees <= 0) {
             System.out.print("Number of Employees Must be Greater than 0, Please Re-enter: ");
             employees = input.nextInt();    
             input.nextLine();            
        }

         System.out.print("Enter Average Salary: ");
         salary = input.nextDouble();
         input.nextLine();

         while(salary <= 0) {
              System.out.print("Average Salary Must be Greater than 0, Please Re-enter: ");
              salary = input.nextDouble();
              input.nextLine();
         }
         // Rest of the Code
 }

要了解为什么需要这样做，请阅读 Java 文档

Answer 3

在 while 循环之外创建一个计数器变量。假设计数器 == 0，在循环结束时将其递增，这样您就不会使用我的解决方案在初始循环中产生问题。

 int counter = 0;
 While(){   
   System.out.print("Enter Division Name: ");
   if(counter != 0){
    input.nextLine();
   } 
   name = input.nextLine();
   counter++;
 }