面向对象练习题

创建四个类：Person类、Student类、Teacher类和Test类

Student类、Teacher类继承Person类

public class Person {
String name;
int age;

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

    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 String say(){
        return "名字为："+name+", 年龄为："+age;
    }
}

public class Student extends  Person{
  double score;

    public Student(String name, int age, double score) {
        super(name, age);
        this.score = score;
    }

    public double getScore() {
        return score;
    }

    public void setScore(double score) {
        this.score = score;
    }
    public String say(){
        return  "学生"+super.say()+", 成绩为"+score;
    }
    //学生私有方法
    public  void study(){
        System.out.println("学生"+getName()+"正在学习Java~");
    }
}

public class Teacher extends Person{
double salary;

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

    public double getSalary() {
        return salary;
    }

    public void setSalary(double salary) {
        this.salary = salary;
    }
    public String say(){
        return  "老师"+super.say()+", 工资为"+salary;
    }
    public  void teach(){
        System.out.println("老师"+getName()+"正在教Java~");
    }
}

public class Test {
    public static void main(String[] args) {
        Person[] people=new  Person[5];
        people[0]=new Person("Tom",38);
        people[1]=new Student("lxl",18,98);
        people[2]=new Student("lky",21,78);
        people[3]=new Teacher("Tm",32,5000);
        people[4]=new Teacher("lll",48,2000);
        for (int i = 0; i <people.length ; i++) {
            System.out.println(people[i].say());
            if (people[i] instanceof Student) {//判断是否为Student类，否则不能访问study方法
                //如果不是，强制转换，向下转型
                Student student = (Student) people[i];
                student.study();
                //也可以使用一条语句代替
//                ((Student)people[i]).study();
            } else if (people[i] instanceof Teacher) {//判断是否为Student类，否则不能访问study方法
                //如果不是，强制转换，向下转型
                Teacher teacher = (Teacher) people[i];
                teacher.teach();
            } else if (people[i] instanceof Person) {
            }else {
                System.out.println("你输入的类型有错误");
            }
        }
    }
}