学生管理系统——Java实现

问题：

 

 代码如下

student类

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

public class student {
    //成员变量
    private String id;
    private String name;
    private int age;
    private String address;
    //空参构造方法
    public student() {}
    //有参构造方法
    public student(String id, String name, int age, String address) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.address = address;
    }
    //成员方法

    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;
    }

    public int getAge() {
        return age;
    }

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

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

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

    public static student add(String id, String name, int age, String address){
        student s = new student();
        s.setId(id);
        s.setName(name);
        s.setAge(age);
        s.setAddress(address);
        return s;
    }
    public static void delect(ArrayList<student> list,String id){
        for (int i = 0; i < list.size(); i++) {
            student stu = list.get(i);
            if(id.equals(stu.getId())){
                list.remove(i);
                return;
            }
            else if(i == list.size() - 1){
                System.out.println("系统没有此学号");
            }
        }
    }
    public  static void change(ArrayList<student> list,String id){
        for (int i = 0; i < list.size(); i++) {
            student stu = list.get(i);
            if(id.equals(stu.getId())){
                Scanner sc = new Scanner(System.in);
                System.out.println("请输入修改学生的name：");
                String name = sc.next();
                stu.setName(name);
                System.out.println("请输入修改学生的age：");
                int age = sc.nextInt();
                stu.setAge(age);
                System.out.println("请输入修改学生的address：");
                String address = sc.next();
                stu.setAddress(address);
                return;
            }
            else if(i == list.size() - 1){
                System.out.println("系统没有此学号");
            }
        }
    }
}

测试类

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

public class student_system_test {
    public static void main(String[] args) {
        ArrayList<student> list = new ArrayList<>();
        Scanner sc = new Scanner(System.in);
        while(true){
            System.out.println("欢迎来到学生管理系统！");
            System.out.println("1.增加学生");
            System.out.println("2.删除学生");
            System.out.println("3.修改学生");
            System.out.println("4.查询学生");
            System.out.println("5.退出系统");
            System.out.println("请输入您的选择：");
            int choice = sc.nextInt();
            if(choice == 1){
                System.out.println("请输入添加学生的id：");
                String id = sc.next();
                System.out.println("请输入添加学生的name：");
                String name = sc.next();
                System.out.println("请输入添加学生的age：");
                int age = sc.nextInt();
                System.out.println("请输入添加学生的address：");
                String address = sc.next();
                list.add(student.add(id,name,age,address));
            }
            else if (choice == 2){
                System.out.println("请输入要删除学生的id：");
                String id = sc.next();
                student.delect(list,id);
            }
            else if(choice == 3){
                System.out.println("请输入要修改学生的id：");
                String id = sc.next();
                student.change(list,id);
            }
            else if(choice == 4){
                if(list.size() == 0){
                    System.out.println("暂无学生信息！");
                }
                for(int i =0;i < list.size();i++){
                    System.out.println(list.get(i));
                }
            }
            else if(choice == 5){
                return;
            }
            else {
                System.out.println("暂无该选项！");
            }
        }
    }
}