用java写一个学生成绩管理系统

好的，下面是一个简单的学生成绩管理系统的Java代码：

import java.util.Scanner;

public class StudentGradeManagementSystem {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int option = 0;
        int num = 0;
        String[] names = new String[100];
        int[] mathScores = new int[100];
        int[] englishScores = new int[100];
        int[] totalScores = new int[100];
        double[] averageScores = new double[100];
        
        while (true) {
            System.out.println("请选择操作：");
            System.out.println("1. 添加学生信息");
            System.out.println("2. 删除学生信息");
            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");
            option = input.nextInt();

            switch (option) {
                case 1:
                    System.out.print("请输入学生姓名：");
                    names[num] = input.next();
                    System.out.print("请输入数学成绩：");
                    mathScores[num] = input.nextInt();
                    System.out.print("请输入英语成绩：");
                    englishScores[num] = input.nextInt();
                    totalScores[num] = mathScores[num] + englishScores[num];
                    averageScores[num] = totalScores[num] / 2.0;
                    num++;
                    System.out.println("添加成功！");
                    break;
                case 2:
                    System.out.print("请输入要删除的学生姓名：");
                    String name = input.next();
                    int index = -1;
                    for (int i = 0; i < num; i++) {
                        if (name.equals(names[i])) {
                            index = i;
                            break;
                        }
                    }
                    if (index == -1) {
                        System.out.println("没有找到该学生！");
                    } else {
                        for (int i = index; i < num - 1; i++) {
                            names[i] = names[i + 1];
                            mathScores[i] = mathScores[i + 1];
                            englishScores[i] = englishScores[i + 1];
                            totalScores[i] = totalScores[i + 1];
                            averageScores[i] = averageScores[i + 1];
                        }
                        num--;
                        System.out.println("删除成功！");
                    }
                    break;
                case 3:
                    System.out.print("请输入要修改的学生姓名：");
                    name = input.next();
                    index = -1;
                    for (int i = 0; i < num; i++) {
                        if (name.equals(names[i])) {
                            index = i;
                            break;
                        }
                    }
                    if (index == -1) {
                        System.out.println("没有找到该学生！");
                    } else {
                        System.out.print("请输入新的数学成绩：");
                        mathScores[index] = input.nextInt();
                        System.out.print("请输入新的英语成绩：");
                        englishScores[index] = input.nextInt();
                        totalScores[index] = mathScores[index] + englishScores[index];
                        averageScores[index] = totalScores[index] / 2.0;
                        System.out.println("修改成功！");
                    }
                    break;
                case 4:
                    System.out.println("学生姓名\t\t数学成绩\t\t英语成绩\t\t总分\t\t平均分");
                    for (int i = 0; i < num; i++) {
                        System.out.println(names[i] + "\t\t\t" + mathScores[i] + "\t\t\t" + englishScores[i] + "\t\t\t" + totalScores[i] + "\t\t\t" + averageScores[i]);
                    }
                    break;
                case 5:
                    System.out.println("谢谢使用！");
                    System.exit(0);
                default:
                    System.out.println("输入错误，请重新输入！");
                    break;
            }
        }
    }
}

这个学生成绩管理系统可以实现添加、删除、修改、查询学生信息的功能。同时，它还可以计算学生的总分和平均分。你可以根据实际需要对代码进行修改和完善。