设计一个学生管理系统
学生管理系统：添加、显示、查询、修改等功能；

import java.util.Scanner;

/**
 * 设计一个：学生管理系统
 * 1.添加学生信息\n 2.显示学生信息\n 3.删除学生信息\n 4.修改学生信息\n5.查看学生信息\n 6.排序\n7.退出
 *
 */

public class Manage {
    // 主模块；
    public static void main(String[] args) {
        Integer[] studentId = new Integer[100];
        Integer[] studentScore = new Integer[100];
        String[] studentName = new String[100];
        int number = 0;
        Integer studentCount = 0;
        int time = 0;
        System.out.println("欢迎进入学生管理系统\n1.添加学生信息\n2.显示学生信息\n" +
                "3.删除学生信息\n4.修改学生信息\n5.查询学生信息\n6.排序\n7.退出");
        while (true) {
            System.out.println("请输入选择：");
            Scanner scanner = new Scanner(System.in);
            number = scanner.nextInt();
            switch (number) {
                case 1:
                    //添加学生信息
                    studentCount = add(studentId, studentName, studentScore,studentCount);
                    System.out.println("添加成功");
                    break;
                case 2:
                    //显示学生信息
                    display(studentId, studentName, studentScore, studentCount);
                    break;
                case 3:
                    //删除学生信息
                    studentCount = delete(studentId, studentName, studentScore,
                            studentCount);
                    break;
                case 4:
                    //修改学生信息
                    update(studentId, studentName, studentScore, studentCount);
                    break;
                case 5:
                    //查询学生信息
                    select(studentId, studentName, studentScore, studentCount);
                    break;
                case 6:
                    //排序
                    Sort(studentId, studentName, studentScore, studentCount);
                    break;
                case 7:
                    //退出
                    System.exit(0);
                    break;
                default:
                    System.out.println("请重新输入1-7之间的整数");
            }
        }
    }

    // 1.添加学生信息块
    public static Integer add(Integer[] studentId, String[] studentName,
                              Integer[] studentScore, int studentCount) {
        System.out.println("请输入学生学号");
        Scanner s1 = new Scanner(System.in);
        studentId[studentCount] = s1.nextInt();
        System.out.println("请输入学生姓名");
        Scanner s2 = new Scanner(System.in);
        studentName[studentCount] = s2.next();
        System.out.println("请输入学生成绩");
        Scanner s3 = new Scanner(System.in);
        studentScore[studentCount] = s3.nextInt();
        studentCount++;
        return studentCount;
    }

    // 2.显示学生信息块
    public static void display(Integer[] studentId, String[] studentName,Integer[] studentScore, int studentCount) {
        String str = "学号"+"\t姓名"+"\t成绩\n";
        for(int i = 0; i < studentCount; i++){
            str = studentId[i] + "\t" + studentName[i] + "\t"
                    + studentScore[i] + "\n";
        }
    }

    // 3.删除学生信息
    public static int delete(Integer[] studentId, String[] studentName,Integer[] studentScore, int studentCount) {
        Integer temp = select(studentId,studentName,studentScore,studentCount);
        System.out.println("是否确定要删除此条信息。是：选1；否：选0");
        Scanner s = new Scanner(System.in);
        int j = s.nextInt();
        switch(j){
            case 0:
                System.out.println("你已取消了删除操作");
                break;
            case 1:
                for(int i=0;i<studentCount;i++){
                    if(studentName.equals(studentName[i])){
                        if(i<studentCount-1){
                            studentId[i] = studentId[i+1];
                            studentName[i] = studentName[i+1];
                            studentScore[i] = studentScore[i+1];
                        }
                        studentId[i] = null;
                        studentName[i] = null;
                        studentScore[i] = null;
                        return studentCount--;
                    }

                }
        }
        return studentCount;
    }

    // 4.修改学生信息块
    public static void update(Integer[] studentId, String[] studentName,Integer[] studentScore, int studentCount) {
        Integer temp = select(studentId, studentName, studentScore, studentCount);
        if(temp == null){
            System.out.println("你输入的信息有误，请重新输入");
        }else{
            System.out.println("请重新输入学号");
            Scanner s1 = new Scanner(System.in);
            studentId[temp] = s1.nextInt();
            System.out.println("请重新输入姓名");
            Scanner s2 = new Scanner(System.in);
            studentName[temp] = s2.next();
            System.out.println("请重新输入分数");
            Scanner s3 = new Scanner(System.in);
            studentScore[temp] = s3.nextInt();
            System.out.println("修改完成");

        }
    }

    // 5.查询学生信息块
    public static Integer select(Integer[] studentId, String[] studentName,Integer[] studentScore, int studentCount) {
        System.out.println("请输入学生姓名");
        Scanner s = new Scanner(System.in);
        String str = s.next();
        for (int i = 0; i < studentCount; i++) {
            if (str.equals(studentName[i]))
                System.out.println("学号"+"\t姓名"+"\t成绩");
            System.out.println(studentId[i] + "\t" + studentName[i] + "\t"
                    + studentScore[i]);
            return studentId[i];
        }
        return null;

    }





    // 6.排序块
    public static void Sort(Integer[] studentId, String[] studentName,Integer[] studentScore, int studentCount) {
        System.out.println("请选择排序方法:1.按学号排序\t2.按成绩排序");
        Scanner s1 = new Scanner(System.in);
        int number = s1.nextInt();
        switch (number) {
            case 1:
                for (int i = 0; i < studentCount; i++) {
                    for (int j = 0; j < studentCount - 1 - i; j++) {
                        if (studentId[j] > studentId[j + 1]) {
                            int tp = studentId[j];
                            studentId[j] = studentId[j + 1];
                            studentId[j + 1] = tp;

                            tp = studentScore[j];
                            studentScore[j] = studentScore[j + 1];
                            studentScore[j + 1] = tp;

                            String tp1 = studentName[j];
                            studentName[j] = studentName[j + 1];
                            studentName[j + 1] = tp1;
                        }
                    }
                }
                display(studentId, studentName, studentScore, studentCount);
                break;

            case 2:
                for (int i = 0; i < studentCount; i++) {
                    for (int j = 0; j < studentCount - 1 - i; j++) {
                        if (studentScore[j] > studentScore[j + 1]) {
                            int tp = studentScore[j];
                            studentScore[j] = studentScore[j + 1];
                            studentScore[j + 1] = tp;

                            tp = studentId[j];
                            studentId[j] = studentId[j + 1];
                            studentId[j + 1] = tp;

                            String tp1 = studentName[j];
                            studentName[j] = studentName[j + 1];
                            studentName[j + 1] = tp1;
                        }
                    }
                }
                display(studentId, studentName, studentScore, studentCount);
                break;
            default:
                System.out.println("请输入1或者2");
        }

    }
}