Question

我在使用驱动程序定义的toString方法打印出一系列StaffMember对象时遇到问题。我一直找不到符号错误，我很困惑我需要在我的驱动程序中替换staffList来使事情顺利进行。

这是我坚持的问题的一部分“你的程序应首先打印所有工作人员（使用StaffMember类的toString（）方法）到终端窗口”

这是我的代码（Staff和StaffMember类来自教科书，并且不需要为作业更改，所以所有问题都在我的驱动程序中。）

public class Staff
{
  private StaffMember[] staffList;

  public Staff ()
  {
    staffList = new StaffMember[6];

    staffList[0] = new Executive ("Sam", "123 Main Line",
    "555-0469", "123-45-6789", 2423.07);

    staffList[1] = new Employee ("Carla", "456 Off Line", "555-0101",
    "987-65-4321", 1246.15);

    staffList[2] = new Employee ("Woody", "789 Off Rocker", "555-0000",
    "010-20-3040", 1169.23);

    staffList[3] = new Hourly ("Diane", "678 Fifth Ave.",
    "555-0690", "958-47-3625", 10.55);

    staffList[4] = new Volunteer ("Norm", "987 Suds Blvd.",
    "555-8374");

    staffList[5] = new Volunteer ("Cliff", "321 Duds Lane",
    "555-7282");

    ((Executive)staffList[0]).awardBonus (500.00);

    ((Hourly)staffList[3]).addHours (40);
  }

    public void payday ()
    {
      double amount;

      for (int count=0; count < staffList.length; count++)
      {
        System.out.println (staffList[count]);
        amount = staffList[count].pay();

        if (amount == 0.0)
          System.out.println ("Thanks!");
        else
          System.out.println ("Paid: " + amount);
        System.out.println ("-----------------------------------");
      }
    }
 }

这是抽象类：

abstract public class StaffMember
{
  protected String name;
  protected String address;
  protected String phone;
//-----------------------------------------------------------------
// Constructor: Sets up this staff member using the specified
// information.
//-----------------------------------------------------------------
  public StaffMember (String eName, String eAddress, String ePhone)
  {
    name = eName;
    address = eAddress;
    phone = ePhone;
  }
//-----------------------------------------------------------------
// Returns a string including the basic employee information.
//-----------------------------------------------------------------
  public String toString()
  {
    String result = "Name: " + name + "\n";
    result += "Address: " + address + "\n";
    result += "Phone: " + phone;
    return result;
  }
//-----------------------------------------------------------------
// Derived classes must define the pay method for each type of
// employee.
//-----------------------------------------------------------------
  public abstract double pay();
}

这就是我到目前为止为司机所做的事情：

import java.util.*;
public class EmployeeBinaryList
{
  public static void main (String args[])
  {
    for (int i = 0; i < staffList.length; i++)
    System.out.println(staffList[i].toString());
  }
}

我尝试过各种各样的东西代替staffList和staffList [i]，但我似乎无法弄明白。非常感谢任何可以帮助我的人

Answer 1

你需要在这里考虑范围。变量范围是可以访问该变量的位置。知道变量范围的最简单方法是使用花括号。变量只能在定义它的大括号内直接访问。因此，staffList在staff类中定义，因此只能在staff类中直接访问。

您必须通过职员类的对象访问该变量：

System.out.println(StaffObject.StaffList) //StaffObject would be an object of the Staff class

但是，在这种情况下，您还需要查看变量是公共变量还是私有变量。私有意味着它不能直接在其类之外访问。因此，在这种情况下，StaffObject.staffList类

之外无法访问Staff

要访问StaffList变量，您需要所谓的Accessor方法。一种公共方法，允许访问变量以进行打印。

所以，这里有什么要做的：

首先，您需要一个员工班级的对象然后，您需要使用该对象访问适当的Accessor方法进行打印

仔细看看代码，很可能是因为这一切。

祝你好运！

Answer 2

package com.cisco.staff;

公共班级工作人员 { private StaffMember [] staffList;

公职人员（） { staffList = new StaffMember [6];

staffList[0] = new Executive ("Sam", "123 Main Line",
"555-0469", "123-45-6789", 2423.07);

staffList[1] = new Employee ("Carla", "456 Off Line", "555-0101",
"987-65-4321", 1246.15);

staffList[2] = new Employee ("Woody", "789 Off Rocker", "555-0000",
"010-20-3040", 1169.23);

staffList[3] = new Hourly ("Diane", "678 Fifth Ave.",
"555-0690", "958-47-3625", 10.55);

staffList[4] = new Volunteer ("Norm", "987 Suds Blvd.",
"555-8374");

staffList[5] = new Volunteer ("Cliff", "321 Duds Lane",
"555-7282");

/ *（（执行）staffList [0]）。awardBonus（500.00）;

((Hourly)staffList[3]).addHours (40);*/

}

public void payday ()
{
  double amount;

  for (int count=0; count < staffList.length; count++)
  {
    System.out.println (staffList[count]);
    amount = staffList[count].pay();

    if (amount == 0.0)
      System.out.println ("Thanks!");
    else
      System.out.println ("Paid: " + amount);
    System.out.println ("-----------------------------------");
  }
}

public StaffMember[] getStaffList() {
    return staffList;
}

public void setStaffList(StaffMember[] staffList) {
    this.staffList = staffList;
}

}

package com.cisco.staff;

抽象公共类StaffMember { protected String name; protected String address; protected String phone;

// --------------------------------------------- -------------------- //构造函数：使用指定的人员设置此人员 //信息 // ------------------------------------------------ ----------------- public StaffMember（String eName，String eAddress，String ePhone） { name = eName; address = eAddress; phone = ePhone; }

// --------------------------------------------- -------------------- //返回包含基本员工信息的字符串。 // ------------------------------------------------ ----------------- public String toString（） { 字符串结果=＆＃34;名称：＆＃34; +名称+＆＃34; \ n＆＃34 ;; 结果+ =＆＃34;地址：＆＃34; +地址+＆＃34; \ n＆＃34 ;; 结果+ =＆＃34;电话：＆＃34; +电话; 返回结果; } // ------------------------------------------------ ----------------- //派生类必须为每种类型定义付费方式 //员工 // ------------------------------------------------ ----------------- public abstract double pay（）; }

package com.cisco.staff;

import java.util.List;

公共类EmployeeBinaryList { public static void main（String args []） { 员工=新员工（）; StaffMember [] staffList = staff.getStaffList（）; for（int i = 0; i＆lt; staffList.length; i ++）的System.out.println（staffList [I]的ToString（））; } }

package com.cisco.staff;

公共班主任延伸职员会员{ protected String somestrString; 受保护的双倍;

public Executive(String eName, String eAddress, String ePhone, String someString , double pay) {
    super(eName, eAddress, ePhone);
    this.somestrString= someString;
    this.somelong=pay;
    // TODO Auto-generated constructor stub
}



@Override
public double pay() {
    // TODO Auto-generated method stub
    return 0;
}

}

package com.cisco.staff;

公共课志愿者延伸职员会员{ protected String somestrString; 受保护的双倍;

public Volunteer(String name, String address, String phone) {
    super(name, address, phone);
    // TODO Auto-generated constructor stub
}

@Override
public double pay() {
    // TODO Auto-generated method stub
    return 0;
}

}

package com.cisco.staff;

public class Employee extends StaffMember {
  protected String somestrString;
  protected double somelong;

public Employee(String name, String address, String phone,
        String somestrString, double somelong) {
    super(name, address, phone); 
    this.somestrString=somestrString;
    this.somelong=somelong;

}

@Override
public double pay() {
    // TODO Auto-generated method stub
    return 0;
}

}

package com.cisco.staff;

 public class Hourly extends StaffMember {
  protected String somestrString;
  protected double hourly;

public Hourly(String eName, String eAddress, String ePhone, String somString, double hourly) {
    super(eName, eAddress, ePhone);
    this.somestrString=somString;
    this.hourly=hourly;
    // TODO Auto-generated constructor stub
}

@Override
public double pay() {
    // TODO Auto-generated method stub
    return 0;
}

}

使用toString打印Staff对象数组

2 个答案: