创建Person类并扩展Person类以创建Student类

//来自 nowjava.com


import java.util.*;


class Main {


    public static void main(String[] args) {


        Scanner scan = new Scanner(System.in);

        String firstName = scan.next();

        String lastName = scan.next();

        int id = scan.nextInt();

        int numScores = scan.nextInt();

        int[] testScores = new int[numScores];

        for (int i = 0; i < numScores; i++) {

            testScores[i] = scan.nextInt();/*时代Java 提供*/

        }

        scan.close();


        Student s = new Student(firstName, lastName, id, testScores);

        s.printPerson();

        System.out.println("Grade: " + s.calculate());

    }

}


class Person {


    private String firstName;

    private String lastName;

    private int idNumber;


    // Constructor

    Person(String firstName, String lastName, int identification) {


        this.firstName = firstName;

        this.lastName = lastName;

        this.idNumber = identification;

    }


    // Print person data

    void printPerson() {


        System.out.println("Name: " + lastName + ", " + firstName + "\nID: " + idNumber);

    }

}


class Student extends Person {


    private int[] testScores;


    Student(String firstName, String lastName, int id, int[] testScores) {


        super(firstName, lastName, id);

        this.testScores = testScores;

    }


    char calculate() {


        int tally = 0;

        for (int score : this.testScores) {

            tally += score;

        }


        int average = (tally / this.testScores.length);


        if (average > 40) {

            if (average >= 90) {

                return 'O';

            }

            if (average >= 80 && average < 90) {

                return 'E';

            }

            if (average >= 70 &a