博客


在这里

插入码片`@[TOC](用ArrayList实现一个简单的学生信息管理系统（增删改查）

public class User {


private String id;

private String name;

public User() {
}

public User(String id, String name) {
    this.id = id;
    this.name = name;
}

public String getId() {
    return id;
}

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

public String getName() {
    return name;
}

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

@Override
public String toString() {
    return "User{" +
            "id='" + id + '\'' +
            ", name='" + name + '\'' +
            '}';
}

import java.util.ArrayList;

import java.util.List;

import java.util.Scanner;

public class TestUser {


public static void main(String[] args) {


List lt = new ArrayList<>();

while (true){


System.out.println(“




学生信息管理系统




”);

System.out.println(“1->查询学生”);

System.out.println(“2->增加学生”);

System.out.println(“3->修改学生”);

System.out.println(“4->删除学生”);

System.out.println(“0->退出系统”);

        int key = new Scanner(System.in).nextInt();

        switch (key){
            case 1:
                System.out.println(lt);
                break;
            case 2:
                System.out.println("id");
                String newid = new Scanner(System.in).nextLine();
                System.out.println("名字");
                String newname = new Scanner(System.in).nextLine();
                User us = new User(newid,newname);
                lt.add(us);
                break;
            case 3:
                System.out.println("id");
                String newid1 = new Scanner(System.in).nextLine();
                System.out.println("名字");
                String newname1 = new Scanner(System.in).nextLine();
                boolean bn =false;
                for (int i =0;i<lt.size();i++){
                    if (newid1.equals(lt.get(i).getId())){
                        User us1 =lt.get(i);
                        us1.setName(newname1);
                        lt.set(i,us1);
                        bn=true;
                    }
                }
               if (bn){
                   System.out.println("成功");
               }else{
                   System.out.println("查无此人");
               }
                break;
            case 4:
                System.out.println("id");
                String newid2 = new Scanner(System.in).nextLine();
                boolean bn1 = false;
                for (int i = 0;i<lt.size();i++){
                    if (newid2.equals(lt.get(i).getId())){
                        lt.remove(lt.get(i));
                        bn1 = true;
                    }
                }
                if (bn1){
                    System.out.println("删除成功");
                }else{
                    System.out.println("没删掉");
                }
                break;
            case 0:
                System.exit(0);

        }
    }
}

}