下面程序定义了Student类和Person类，并在Main类中对它们进行了演示。演示结果如样例输出所示。请将程序填写完整。

Question

题目描述
下面程序定义了Student类和Person类，并在Main类中对它们进行了演示。演示结果如样例输出所示。请将程序填写完整。

class Person {

    protected String name;
    protected char sex;

    【1】 {//空1
        this.name = name;
        this.sex = sex;
    }

    String name() {
        return name;
    }

    char sex() {
        return sex;
    }

    public String toString() {
        String s = new String(name + "(sex: " + sex + ")");
        return s;
    }

}

class Student extends Person {
    protected String id;

    Student(String name, char sex) {
        【2】;// 空2
    }

    Student(String name, char sex, String id) {
        super(name, sex);
        this.id = id;
    }

    public String toString() {
        String s = new String(name + "(sex:" + sex);
        【3】//空3
        s += ")";
        return s;
    }

    【4】 {//空4
        this.id = id;
    }    

}

public class Main {

    public static void main(String[] args) {
        Person frank = new Person("Frank", 'M');
        Student alice = new Student("Alice", 'F');
        System.out.println("frank: " + frank);
        System.out.println("alice: " + alice);
        Person tom = alice;
        System.out.println("tom: " + tom);
        【5】;// 空5
        System.out.println("tom: " + tom);
    }

}

输出样例
frank: Frank(sex: M)
alice: Alice(sex:F)
tom: Alice(sex:F)
tom: Alice(sex:F;id:00000001)

Answer 1

1: public Person(String name, char sex)

2: super(name, sex)

3:
if (this.id != null) {
  s += ";id=" + this.id;
}

4: public void setId(String id)

5: alice.setId("00000001")