100521-多态性练习

Java继承与多态实例

最新推荐文章于 2025-12-05 17:02:52 发布

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该博客展示了Java中类的继承、多态性概念。通过Person、Student和Graduate类的层级关系，演示了如何使用getInfo()方法获取不同对象的信息，并使用instanceof关键字检查对象类型，展示多态特性。

package com.neal.exer1;

class Person{
    protected String name = "person";
    protected int age = 50;
    public String getInfo(){
        return "Name: " + name + "\n" + "age: " + age;
    }
}

class Student extends Person{
    protected String school = "pku";
    public String getInfo(){
        return "Name: " + name + "\nage: " + age + "\nschool: " + school;
    }
}

class Graduate extends Student{
    public String major="IT";
    public String getInfo(){
        return "Name: " + name + "\nage: "+ age + "\nschool: "+ school
                + "\nmajor: "+ major;
    }
}
public class InstanceTest {
    public static void main(String[] args) {
        InstanceTest test = new InstanceTest();
        test.method(new Student());
    }
    public void method(Person e){
        //虚拟化调用
        String info = e.getInfo();
        System.out.println(info);

        if (e instanceof Graduate){
            System.out.println("a graduated student");
            System.out.println("a student");
            System.out.println("a person");
        }else if(e instanceof Student){
            System.out.println("a student");
            System.out.println("a person");
        }else {
            System.out.println("a person");
        }


    }
}