java/w5/PolymorphismTest.java

abstract class Person {
    protected String name;
    protected int age;

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

    public abstract void display();
}

class Student extends Person {
    int studentId;
    String major;

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

    @Override
    public void display() {
        System.out.println("学生信息 - 姓名:" + name + ", 年龄:" + age +
                         ", 学号:" + studentId + ", 专业:" + major);
    }
}

class Teacher extends Person {
    String subject;
    double salary;

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

    @Override
    public void display() {
        System.out.println("教师信息 - 姓名:" + name + ", 年龄:" + age +
                         ", 科目:" + subject + ", 薪资:" + salary);
    }
}

public class PolymorphismTest {
    public static void addPerson(Person[] array, int count, Person p) {
        if (count < array.length) {
            array[count] = p;
        }
    }

    public static void main(String[] args) {
        Person[] persons = new Person[10];
        int count = 0;

        System.out.println("=== 挑战题测试 ===");

        persons[count++] = new Student("张三", 20, 1001, "计算机科学");
        persons[count++] = new Student("李四", 22, 1002, "软件工程");
        persons[count++] = new Teacher("王老师", 35, "数据结构", 8000);
        persons[count++] = new Teacher("刘老师", 40, "算法分析", 9000);

        System.out.println("添加成功！共添加 " + count + " 人\n");

        System.out.println("=== 所有人员信息 ===");
        for (int i = 0; i < count; i++) {
            persons[i].display();
        }

        System.out.println("\n=== 思考题解答 ===");
        System.out.println("多态优势：addPerson(Person p) 统一处理不同类型");
        System.out.println("添加特定属性问题：使用 instanceof 判断类型后强制转换");
    }
}