public class Undergraduate extends Student { private String degree; public Undergraduate(String name, int age, String degree) { super(name, age); this.degree = degree; } @Override public void show() { super.show(); System.out.println("学位：" + degree); } } public class Student { private String name; private int age; public Student(String name, int age) { this.name = name; this.age = age; } public void show(){ System.out.println("姓名：" + name + "\n年龄：" + age); } } public class TestStudent { public static void main(String[] args) { Student s1 = new Student("yhviews", 20); Undergraduate u1 = new Undergraduate("zeal", 22, "本科"); s1.show(); u1.show(); } }