Java基础 用数组写的学生管理系统

package sc.strong; import java.util.Scanner; public class student { static int num; static int[] stuId = new int[100]; static String[] stuName = new String[100]; static String[] stuSex = new String[100]; static Scanner sc = new Scanner(System.in); public static void main(String[] args) { // stuId[0] = 1; // stuName[0] = "王大"; // stuSex[0] = "男"; menu(); } private static void menu() { System.out.println("---菜单---"); System.out.println("1.添加学生"); System.out.println("2.删除学生"); System.out.println("3.修改学生"); System.out.println("4.查询学生"); num = sc.nextInt(); switch (num) { case 1: tianjia(); break; case 2: shanchu(); break; case 3: xiugai(); break; case 4: chaxun(); break; default: break; } } private static void shanchu() { System.out.println("--请输入需要删除的学号"); int id = sc.nextInt(); if (id < 100) { stuId[id - 1] = 0; stuName[id - 1] = null; stuSex[id - 1] = null; System.out.println("删除成功"); } else { System.out.println("请输入正确学号（100以内）"); } menu(); } private static void chaxun() { // TODO Auto-generated method stub System.out.println("--查询学生请输入学号"); System.out.println("1.---学号查询"); System.out.println("2.---查询所有"); int num = sc.nextInt(); if (num == 1) { System.out.println("请输入学号"); int i = sc.nextInt(); System.out.println("学号:" + stuId[i - 1] + " 姓名:" + stuName[i - 1] + " 性别:" + stuSex[i - 1]); menu(); } else if (num == 2) { for (int j = 0; j < stuId.length; j++) { System.out.println("学号:" + stuId[j] + " 姓名:" + stuName[j] + " 性别:" + stuSex[j]); } } menu(); } private static void xiugai() { // TODO Auto-generated method stub System.out.println("--修改学生：请输入学号"); int i = sc.nextInt(); if (i < stuId.length) { System.out.println("输入新的姓名"); String name = sc.next(); stuName[i - 1] = name; System.out.println("输入性别"); String sex = sc.next(); stuSex[i - 1] = sex; System.out.println("新的信息为: " + "学号:" + stuId[i - 1] + " 姓名:" + stuName[i - 1] + " 性别:" + stuSex[i - 1]); } else { System.out.println("输入有误，请输入正确学号（100以内）"); } menu(); } private static void tianjia() { // TODO Auto-generated method stub System.out.println("--添加学生：请输入学号"); int id = sc.nextInt(); if (id < stuId.length) { System.out.println("请输入姓名"); String name = sc.next(); System.out.println("请输入性别"); String sex = sc.next(); stuId[id - 1] = id; stuName[id - 1] = name; stuSex[id - 1] = sex; } else { System.out.println("请输入正确的学号（100以内）"); } menu(); } }