【java学习】第七天(作业4)

第十三题

代码

package com.quange.homework;

public class Homework13 {
    public static void main(String[] args) {

        // 打印信息
        Student student = new Student("小明", 17, '男' , "20220101");
        student.printInfo();
        System.out.println("--------------------------------");
        Teacher teacher = new Teacher("老韩", 40, '男', 20);
        teacher.printInfo();

        // 定义对象数组
        Person[] people = new Person[4];
        people[0] = new Student("小明", 18, '男', "20220101");
        people[1] = new Student("小王", 17, '男', "20220102");
        people[2] = new Teacher("老韩", 40, '男', 20);
        people[3] = new Teacher("老王", 50, '男', 30);

        // 创建对象
        Homework13 homework13 = new Homework13();
        homework13.bubbleSort(people);

        // 输入排序后的对象
        for (int i = 0; i < people.length; i++) {
            System.out.println(people[i]);
        }
        System.out.println("----------------------------");
        // 遍历数组，调用test方法
        for (int i = 0; i < people.length; i++) {
            homework13.test(people[i]);
        }

    }
    // 方法，完成年龄的从大到小排序
    public void bubbleSort(Person[] people){
        // 定义变量
        Person tmp = null;
        for (int i = 0; i < people.length -1; i++) {
            for (int j = 0; j < people.length -1 -i; j++) {
                if (people[j].getAge() < people[j+1].getAge()){
                    tmp = people[j];
                    people[j] = people[j+1];
                    people[j+1] = tmp;
                }
            }
        }
    }

    // 方法，这里使用向下转型和类型判断
    public void test(Person p){
        if (p instanceof Student){ // p的运行类型如果是Student
            ((Student) p).study();
        }else if (p instanceof Teacher){ //p的运行类型如果是Teacher
            ((Teacher) p).teach();
        }else {
            System.out.println("do nothing....");
        }
    }

    //父类 Person 类
    static class Person{
        // 共同属性
        private String name; // 姓名
        private int age;  // 年龄
        private char sex; // 性别

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

        public String getName() {
            return name;
        }

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

        public int getAge() {
            return age;
        }

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

        public char getSex() {
            return sex;
        }

        public void setSex(char sex) {
            this.sex = sex;
        }

        // 共有的方法
        public String play(){
            return name + "爱玩";
        }

        public String basicInfo(){
            return "姓名: " + name + "\n年龄：" + age + "\n性别：" + sex;
        }

        @Override
        public String toString() {
            return "Person{" +
                    "name='" + name + '\'' +
                    ", age=" + age +
                    ", sex=" + sex +
                    '}';
        }
    }
    // 子类 Stduent
    static class Student extends Person{
        // 特有属性
        private String stu_id; // 学号

        public Student(String name, int age, char sex, String stu_id) {
            super(name, age, sex);
            this.stu_id = stu_id;
        }

        // 特有方法
        public void study(){
            System.out.println(getName() + "承诺，我会好好学习");
        }

        @Override
        public String play() {
            return super.play() + "足球";
        }

        @Override
        public String toString() {
            return "Student{" +
                    "stu_id='" + stu_id + '\'' +
                    '}' + super.toString();
        }

        public void printInfo(){
            System.out.println("学生的信息：");
            System.out.println(super.basicInfo());
            System.out.println("学号：" + stu_id);
            study();
            System.out.println(play());
        }
    }

    // 子类 Teacher
    static class Teacher extends Person{
        // 特有属性
        private int work_age; // 工龄

        public Teacher(String name, int age, char sex, int work_age) {
            super(name, age, sex);
            this.work_age = work_age;
        }

        // 特有方法
        public void teach(){
            System.out.println( getName() + "承诺，我会认真教学。");
        }

        @Override
        public String play() {
            return super.play() + "象棋";
        }

        @Override
        public String toString() {
            return "Teacher{" +
                    "work_age=" + work_age +
                    '}' + super.toString();
        }

        public void printInfo(){
            System.out.println("老师的信息：");
            System.out.println(super.basicInfo());
            System.out.println("工龄：" + work_age);
            teach();
            System.out.println(play());
        }
    }
}

输出

学生的信息：
姓名: 小明
年龄：17
性别：男
学号：20220101
小明承诺，我会好好学习
小明爱玩足球
--------------------------------
老师的信息：
姓名: 老韩
年龄：40
性别：男
工龄：20
老韩承诺，我会认真教学。
老韩爱玩象棋
Teacher{work_age=30}Person{name='老王', age=50, sex=男}
Teacher{work_age=20}Person{name='老韩', age=40, sex=男}
Student{stu_id='20220101'}Person{name='小明', age=18, sex=男}
Student{stu_id='20220102'}Person{name='小王', age=17, sex=男}
----------------------------
老王承诺，我会认真教学。
老韩承诺，我会认真教学。
小明承诺，我会好好学习
小王承诺，我会好好学习

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