class Person{ public String name; public String getName(){ return name; } } class Employee extends Person{ public int employeeNumber; public int getEmployeeNumber(){ return employeeNumber; } } class Manager extends Employee{ public String responsibilities; public String getResponsibilities(){ return responsibilities; } } public class Exam { public static void main(String args[]){ Employee Li = new Employee(); Li.name="Li Ming"; Li.employeeNumber=123456; System.out.println(Li.getName()); System.out.println(Li.getEmployeeNumber()); Manager he = new Manager(); he.name="He Xia"; he.employeeNumber=543469; he.responsibilities="Internet project"; System.out.println(he.getName()); System.out.println(he.getResponsibilities()); } }

你的问题是关于Java类继承的。代码定义了一个Person类，一个Employee类，一个Manager类。Employee和Manager都是Person的子类，Manager是Employee的子类。代码在main方法中创建了Employee和Manager对象，然后打印它们的姓名和员工编号或职责。

相关问题

设计一个抽象类名字为 Person,它的子类为Student和 Employee；person类有name以及toString方法；student有 status属性(freshman, sophomore, junior, or senior),定义status 为常量;Employee类 有office, salary；分别定义各个类的有参构造方法，Person(String name)、Student（String name,int status）、Employee(String name,String office,double salary),注意需要在子类构造方法第一句调用父类有参构造方法，为子类也实现toString方法。编写测试类定义一个数组存放每个非抽象类对象（Student和 Employee），然后利用多态调用toString方法打印各个对象的所有属性信息。(为了减少书写量，只需要为name属性完成get和set方法，其他属性不用写)

以下是根据您的要求设计的抽象类和子类的代码：

// Person抽象类
public abstract class Person {
    private String name;

    public Person(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public abstract String toString();
}

// Student子类
public class Student extends Person {
    private static final int FRESHMAN = 1;
    private static final int SOPHOMORE = 2;
    private static final int JUNIOR = 3;
    private static final int SENIOR = 4;

    private int status;

    public Student(String name, int status) {
        super(name);
        this.status = status;
    }

    public String getStatus() {
        String statusStr;
        switch (status) {
            case FRESHMAN:
                statusStr = "Freshman";
                break;
            case SOPHOMORE:
                statusStr = "Sophomore";
                break;
            case JUNIOR:
                statusStr = "Junior";
                break;
            case SENIOR:
                statusStr = "Senior";
                break;
            default:
                statusStr = "Unknown";
                break;
        }
        return statusStr;
    }

    @Override
    public String toString() {
        return "Name: " + getName() + ", Status: " + getStatus();
    }
}

// Employee子类
public class Employee extends Person {
    private String office;
    private double salary;

    public Employee(String name, String office, double salary) {
        super(name);
        this.office = office;
        this.salary = salary;
    }

    public String getOffice() {
        return office;
    }

    public double getSalary() {
        return salary;
    }

    @Override
    public String toString() {
        return "Name: " + getName() + ", Office: " + getOffice() + ", Salary: " + getSalary();
    }
}

// 测试类
public class Test {
    public static void main(String[] args) {
        Person[] people = new Person[4];
        people[0] = new Student("Alice", 3);
        people[1] = new Student("Bob", 2);
        people[2] = new Employee("Charlie", "HR", 50000);
        people[3] = new Employee("Dave", "Finance", 60000);

        for (Person person : people) {
            System.out.println(person.toString());
        }
    }
}

这段代码定义了一个抽象类`Person`，它有一个`name`属性和一个`toString`方法。`Student`和`Employee`都是`Person`的子类，分别有额外的属性和构造方法，并且都实现了`toString`方法。在测试类中，使用多态性将`Student`和`Employee`对象存储在`Person`类型的数组中，并通过调用`toString`方法打印出各个对象的属性信息。

定义一个Person类和它的子类Employee。Person类有姓名、年龄和电话号码等私有成员变量，为私有成员变量分别定义set和get方法；定义一个方法showMessage()输出Person类的成员变量。Employee类有部门、工资等私有成员变量，定义一个方法showMessage()输出Employee的基本信息（含姓名、年龄和电话号码）。Person类和Employee类均定义带参和不带参的构造方法实现对其成员变量的初始化。定义一个public类，在其main()方法中分别基于父类和子类创建两个对象，通过构造方法分别为父类和子类的成员变量赋值，然后分别调用父类和子类的showMessage()方法输出其基本信息。使用java编写

在 Java 中，可以使用如下代码定义 Person 类和 Employee 类：

public class Person {
  private String name;
  private int age;
  private String phone;

  public Person() {
    // 默认构造方法
  }

  public Person(String name, int age, String phone) {
    this.name = name;
    this.age = age;
    this.phone = phone;
  }

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

  public String getName() {
    return name;
  }

  public void setAge(int age) {
    this.age = age;
  }

  public int getAge() {
    return age;
  }

  public void setPhone(String phone) {
    this.phone = phone;
  }

  public String getPhone() {
    return phone;
  }

  public void showMessage() {
    System.out.println("姓名: " + name + ", 年龄: " + age + ", 电话: " + phone);
  }
}

public class Employee extends Person {
  private String department;
  private double salary;

  public Employee() {
    // 默认构造方法
  }

  public Employee(String name, int age, String phone, String department, double salary) {
    super(name, age, phone);
    this.department = department;
    this.salary = salary;
  }

  public void setDepartment(String department) {
    this.department = department;
  }

  public String getDepartment() {
    return department;
  }

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

  public double getSalary() {
    return salary;
  }

  public void showMessage() {
    super.showMessage();
    System.out.println("部门: " + department + ", 工资: " + salary);
  }
}

然后，可以在另一个 public 类中的 main 方法中创建 Person 类和 Employee 类的对象，并调用 showMessage 方法输出其基本信息：

public class Test {
  public static void main(String[] args) {
    Person p = new Person("张三", 25, "123456");
    p.showMessage();

    Employee e = new Employee("李四", 30, "654321", "市场部", 8000);
    e.showMessage();
  }
}

输出结果如下：

姓名: 张三, 年龄: 25, 电话: 123456