如何从数组列表中删除用户？ [英] How to remove a user from an Array List?

问题描述

package main;
import java.util.ArrayList;

public class UserGroup {

  ArrayList<User> userGroup = new ArrayList<>();
  User userOne;
  public UserGroup() {
    addUser(new User("lnb1g16", "Student", "Lee"));
    addUser(new User("hpf1g17", "Staff", "Harry"));
    addUser(new User("jks1g25", "Student", "Jordon"));
  }

  public void addUser(User inUser) {
    //userGroup.add(new User("LeeB123", "Staff", "Lee"));
    userGroup.add(inUser);
  }

  public ArrayList<User> getUserGroup() {
    return userGroup;
  }

  public void removeFirstUser() {
    userGroup.remove(0)
  }
}

我已经尝试创建一个删除第一个用户并且似乎正在编译的方法，但在编译程序时实际上并没有删除用户。关于如何解决这个问题的任何想法都会很棒，谢谢。

I've tried creating a method that removes the first user and seems to be compiling but does not actually remove the user when the program is compiled. Any ideas on how to fix this would be great, thanks.

调用程序的主要方法

package main;

public class Main{
  public static void main(String[] args) {
    for (int counter=2; counter<=40; counter+=2) {
      System.out.println(counter);
    }
    System.out.println("For loop complete.");

    int counter = 1;
    int increment = 2;
    int loopexeccounter = 0;
    while (counter <= 500) {
      loopexeccounter = loopexeccounter + 1;
      System.out.println(counter);
      counter = counter + increment++;
    }
    System.out.print("This loop iteratted "+loopexeccounter+" times.\n");

    {
      //public User callUserGroup;   
      UserGroup userGroupObject = new UserGroup();

      for (User curUser : userGroupObject.getUserGroup()) {
        System.out.println(curUser.toString());
      }
    }
  }
}

声明用户详细信息的用户方法

package main;

class User {

  String username;
  String userType;
  String name;

  User(String username, String userType, String name) {
    this.username = username;
    this.userType = userType;
    this.name = name;
  }

  public String getUsername() {
    return username;
  }

  public String getUserType() {
    return userType;
  }

   public String getName() {         
     return name;
  }

   public String setUserType(String admin) {
     return userType = admin;
   }

   @Override
   public String toString() {
     return username + " " + userType;
   }  
}

推荐答案

这是工作良好：

`  public static void main(String[] args) {
    UserGroup MyUser = new UserGroup();
    for (User curUser : MyUser.getUserGroup()) {
        System.out.println(curUser.toString());
      }
    MyUser.removeFirstUser();
    System.out.println("your user removed!");
    for (User curUser : MyUser.getUserGroup()) {
        System.out.println(curUser.toString());
      }
  }`

结果：

`User@4554617c 1
User@74a14482 2
User@1540e19d 3
your user removed!
User@74a14482 1
User@1540e19d 2`

这篇关于如何从数组列表中删除用户？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！