声明一个抽象类Person,此类中定义无参无返回值得抽象方法print(); 声明Teacher类、Student类,均继承自Person类,并复写了print()方法; 运用多态方式实例化子类对象并调用print()方法打印输出信息;
时间: 2024-03-12 13:42:53 浏览: 27
代码如下:
```java
// 定义抽象类 Person
abstract class Person {
public abstract void print();
}
// 定义 Teacher 类,继承自 Person
class Teacher extends Person {
@Override
public void print() {
System.out.println("我是一名老师。");
}
}
// 定义 Student 类,继承自 Person
class Student extends Person {
@Override
public void print() {
System.out.println("我是一名学生。");
}
}
// 测试类
public class Test {
public static void main(String[] args) {
// 多态方式实例化子类对象
Person p1 = new Teacher();
Person p2 = new Student();
// 调用 print() 方法打印输出信息
p1.print(); // 输出:我是一名老师。
p2.print(); // 输出:我是一名学生。
}
}
```
运行结果:
```
我是一名老师。
我是一名学生。
```
相关问题
1.编写程序:在教学管理系统中有教师、教学管理人员和学生,定义一个抽象类 Person,用 Teacher、 Manager、 Student去继承 Person类,完成类的设计.
以下是一个可能的程序实现:
```python
# 定义 Person 抽象类
from abc import ABC, abstractmethod
class Person(ABC):
def __init__(self, name, age, gender):
self.name = name
self.age = age
self.gender = gender
@abstractmethod
def introduce(self):
pass
# 定义 Teacher 类,继承自 Person 类
class Teacher(Person):
def __init__(self, name, age, gender, department):
super().__init__(name, age, gender)
self.department = department
def introduce(self):
print(f"I am a teacher. My name is {self.name}, and I am {self.age} years old. I work in the {self.department} department.")
# 定义 Manager 类,继承自 Person 类
class Manager(Person):
def __init__(self, name, age, gender, title):
super().__init__(name, age, gender)
self.title = title
def introduce(self):
print(f"I am a manager. My name is {self.name}, and I am {self.age} years old. My title is {self.title}.")
# 定义 Student 类,继承自 Person 类
class Student(Person):
def __init__(self, name, age, gender, grade):
super().__init__(name, age, gender)
self.grade = grade
def introduce(self):
print(f"I am a student. My name is {self.name}, and I am {self.age} years old. I am in grade {self.grade}.")
```
在这个程序中,我们定义了一个 `Person` 抽象类,它有一个抽象方法 `introduce`,用于在子类中实现自我介绍。然后,我们定义了三个子类:`Teacher`、`Manager` 和 `Student`,它们都继承自 `Person` 类,并实现了 `introduce` 方法。每个类都有一些特定的属性,例如 `Teacher` 类有一个 `department` 属性,表示教学部门。
使用这个程序,我们可以创建不同类型的人物对象,例如:
```python
t = Teacher("Tom", 35, "male", "mathematics")
t.introduce() # 输出:I am a teacher. My name is Tom, and I am 35 years old. I work in the mathematics department.
m = Manager("Mary", 40, "female", "dean")
m.introduce() # 输出:I am a manager. My name is Mary, and I am 40 years old. My title is dean.
s = Student("Sam", 18, "male", 12)
s.introduce() # 输出:I am a student. My name is Sam, and I am 18 years old. I am in grade 12.
```
这样,我们就完成了题目中要求的类的设计。
设计一个java程序,如下:1 Person类(抽象类): 属性:int id, String name, LocalDate birthDate。 方法:构造方法(id, name, year, month, dayOfMonth); id与birthDate的getter方法; name的getter/setter方法; 抽象方法String getPersonInfo(),该方法之所以声明为抽象是因为其在子类返回的信息与子类特有属性相关。 Student类继承自Person类: 属性:int enrollmentYear, String clazzName。 方法:构造方法(id, name, year, month, dayOfMonth, enrollmentYear, clazzName),建议使用super复用Person的构造方法; 覆盖父类的 getPersonInfo()方法,返回"Student-enrollmentYear-name" Teacher类继承自Person: 属性:String department, double salary。 方法:构造方法(id, name, year, month, dayOfMonth, department, salary),建议使用super复用Person的构造方法; 覆盖父类的 getPersonInfo()方法,返回"Teacher-department-name" main方法包含: 输入 : 产生n个对象 如果要生成Student对象则依次输入:姓名 年 月 日 入学年份 班级 如果要生成Teacher对象则依次输入:姓名 年 月 日 系 薪水 输出 : 学生人数,教师人数 n个对象getPersonNumber 输入样例: 6 Liz 1986 10 10 CS 2000 Tom 1978 5 7 CS 2500.5 Sally 2000 1 3 2018 Net01 Jerry 1988 6 7 Mechanical 1990 Eliza 2001 2 5 2019 Software02 Li 1978 5 7 cs 2400 输出样例: Teacher 4人 Student 2人 Teacher-CS-Liz Teacher-CS-Tom Student-2018-Sally Teacher-Mechanical-Jerry Student-2019-Eliza Teacher-cs-Li
以下是Java代码实现:
```java
import java.time.LocalDate;
import java.util.ArrayList;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
ArrayList<Person> persons = new ArrayList<>();
System.out.print("请输入对象的个数:");
int n = scanner.nextInt();
scanner.nextLine();
for (int i = 0; i < n; i++) {
System.out.print("请输入对象类型(1为学生,2为教师):");
int type = scanner.nextInt();
scanner.nextLine();
System.out.print("请输入姓名:");
String name = scanner.nextLine();
System.out.print("请输入出生年份:");
int year = scanner.nextInt();
System.out.print("请输入出生月份:");
int month = scanner.nextInt();
System.out.print("请输入出生日:");
int dayOfMonth = scanner.nextInt();
if (type == 1) {
System.out.print("请输入入学年份:");
int enrollmentYear = scanner.nextInt();
System.out.print("请输入班级名称:");
String clazzName = scanner.next();
persons.add(new Student(name, year, month, dayOfMonth, enrollmentYear, clazzName));
} else if (type == 2) {
System.out.print("请输入系别名称:");
String department = scanner.next();
System.out.print("请输入薪水:");
double salary = scanner.nextDouble();
persons.add(new Teacher(name, year, month, dayOfMonth, department, salary));
}
}
int studentCount = 0;
int teacherCount = 0;
for (Person person : persons) {
if (person instanceof Student) {
studentCount++;
} else if (person instanceof Teacher) {
teacherCount++;
}
System.out.println(person.getPersonInfo());
}
System.out.println("学生人数:" + studentCount);
System.out.println("教师人数:" + teacherCount);
}
}
abstract class Person {
protected int id;
protected String name;
protected LocalDate birthDate;
public Person(int id, String name, int year, int month, int dayOfMonth) {
this.id = id;
this.name = name;
this.birthDate = LocalDate.of(year, month, dayOfMonth);
}
public int getId() {
return id;
}
public LocalDate getBirthDate() {
return birthDate;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public abstract String getPersonInfo();
}
class Student extends Person {
private int enrollmentYear;
private String clazzName;
public Student(String name, int year, int month, int dayOfMonth, int enrollmentYear, String clazzName) {
super(0, name, year, month, dayOfMonth);
this.enrollmentYear = enrollmentYear;
this.clazzName = clazzName;
}
@Override
public String getPersonInfo() {
return "Student-" + enrollmentYear + "-" + name;
}
}
class Teacher extends Person {
private String department;
private double salary;
public Teacher(String name, int year, int month, int dayOfMonth, String department, double salary) {
super(0, name, year, month, dayOfMonth);
this.department = department;
this.salary = salary;
}
@Override
public String getPersonInfo() {
return "Teacher-" + department + "-" + name;
}
}
```