java实现学生成绩管理

以下是一个简单的Java学生成绩管理程序：

import java.util.ArrayList;
import java.util.Scanner;

public class StudentGradeManager {

    public static void main(String[] args) {
        ArrayList<Student> students = new ArrayList<>();
        Scanner scanner = new Scanner(System.in);

        while (true) {
            System.out.println("请选择操作：");
            System.out.println("1. 添加学生");
            System.out.println("2. 删除学生");
            System.out.println("3. 修改学生信息");
            System.out.println("4. 查询学生信息");
            System.out.println("5. 退出程序");

            int choice = scanner.nextInt();
            switch (choice) {
                case 1:
                    addStudent(students, scanner);
                    break;
                case 2:
                    deleteStudent(students, scanner);
                    break;
                case 3:
                    updateStudent(students, scanner);
                    break;
                case 4:
                    queryStudent(students, scanner);
                    break;
                case 5:
                    System.exit(0);
                    break;
                default:
                    System.out.println("输入错误，请重新选择！");
            }
        }
    }

    private static void addStudent(ArrayList<Student> students, Scanner scanner) {
        System.out.println("请输入学生姓名：");
        String name = scanner.next();
        System.out.println("请输入学生学号：");
        String id = scanner.next();
        System.out.println("请输入学生年龄：");
        int age = scanner.nextInt();
        System.out.println("请输入学生性别：");
        String gender = scanner.next();
        System.out.println("请输入学生成绩：");
        double grade = scanner.nextDouble();

        Student student = new Student(name, id, age, gender, grade);
        students.add(student);
        System.out.println("添加成功！");
    }

    private static void deleteStudent(ArrayList<Student> students, Scanner scanner) {
        System.out.println("请输入要删除的学生的学号：");
        String id = scanner.next();

        for (int i = 0; i < students.size(); i++) {
            if (students.get(i).getId().equals(id)) {
                students.remove(i);
                System.out.println("删除成功！");
                return;
            }
        }

        System.out.println("没有找到该学号的学生！");
    }

    private static void updateStudent(ArrayList<Student> students, Scanner scanner) {
        System.out.println("请输入要修改的学生的学号：");
        String id = scanner.next();

        for (Student student : students) {
            if (student.getId().equals(id)) {
                System.out.println("请输入修改后的学生姓名：");
                String name = scanner.next();
                System.out.println("请输入修改后的学生年龄：");
                int age = scanner.nextInt();
                System.out.println("请输入修改后的学生性别：");
                String gender = scanner.next();
                System.out.println("请输入修改后的学生成绩：");
                double grade = scanner.nextDouble();

                student.setName(name);
                student.setAge(age);
                student.setGender(gender);
                student.setGrade(grade);

                System.out.println("修改成功！");
                return;
            }
        }

        System.out.println("没有找到该学号的学生！");
    }

    private static void queryStudent(ArrayList<Student> students, Scanner scanner) {
        System.out.println("请输入要查询的学生的学号：");
        String id = scanner.next();

        for (Student student : students) {
            if (student.getId().equals(id)) {
                System.out.println(student);
                return;
            }
        }

        System.out.println("没有找到该学号的学生！");
    }

}

class Student {
    private String name;
    private String id;
    private int age;
    private String gender;
    private double grade;

    public Student(String name, String id, int age, String gender, double grade) {
        this.name = name;
        this.id = id;
        this.age = age;
        this.gender = gender;
        this.grade = grade;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public double getGrade() {
        return grade;
    }

    public void setGrade(double grade) {
        this.grade = grade;
    }

    @Override
    public String toString() {
        return "学生信息：" +
                "姓名：" + name +
                ", 学号：" + id +
                ", 年龄：" + age +
                ", 性别：" + gender +
                ", 成绩：" + grade;
    }
}

该程序包含以下功能：

1. 添加学生信息：包括姓名、学号、年龄、性别、成绩；
2. 删除学生信息：根据学号删除学生信息；
3. 修改学生信息：根据学号修改学生的姓名、年龄、性别、成绩；
4. 查询学生信息：根据学号查询学生的所有信息；
5. 退出程序。

程序使用了一个`Student`类来表示学生信息，并使用了一个`ArrayList`来存储所有学生的信息。在程序运行时，用户可以根据菜单选择需要进行的操作。每个操作都会调用相应的函数来完成。