如何查看所有 ArrayList 条目并删除特定条目？

Question

我有一个客户，客户和主类。我在客户类中有一个 ArrayList 来存储每个客户。我想我已经成功添加了客户。如何在 ArrayList 中显示所有客户以及如何删除特定客户？我正在尝试在客户类中创建一个方法并在主类中调用它。

客户类别：

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

public class customer {


    //create variables
    private int Id;
    private String firstName;
    private String lastName;


    public customer() {

    }


    //setters and getters
    public int getId() {
        return Id;
    }

    public void setId(int id) {
        Id = id;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) throws InputValidationException {
        if (firstName.matches("\\p{Upper}(\\p{Lower}){2,20}")) {
        } else {
            throw new InputValidationException();
        }
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) throws InputValidationException {
        if (lastName.matches("\\p{Upper}(\\p{Lower}){2,20}")) {
        } else {
            throw new InputValidationException();
        }
        this.lastName = lastName;
    }



    //constructor
    public customer(int Id, String firstName, String lastName) {
        this.Id = Id;
        this.firstName = firstName;
        this.lastName = lastName;
       }

    //get user input
    public void customerInfo() {
        Scanner input = new Scanner(System.in);

        {
            while (true) {
                //ask user for input and get input
                System.out.println("Enter id (press 'q' to quit): ");
                String temp = input.nextLine();
                if (temp.equals("q")) break;

                int id = Integer.parseInt(temp);

                System.out.println("Enter first name:");
                String firstName = input.nextLine();

                System.out.println("Enter last name:");
                String lastName = input.nextLine();


                //add customer
                customers.add(new customer(id, firstName, lastName));

            }

        }
    }
    public  void displayCustomers() {
        System.out.println("Customer List : ");

        }
    }

客户类别：

import java.util.ArrayList;
//creates an array of the customers

public final class customers {
    public static ArrayList<customer> customers;

        public customers() {
            customers = new ArrayList<customer>();
        }


    public static void add(customer customer) {
    }

}

主类：

public class Main {
    public static void main(String[] args) {

        customer customerInfoObject = new customer();
        customerInfoObject.customerInfo();

        customer displayCustomersObject = new customer();
        displayCustomersObject.displayCustomers();

    }
}

Answer 1

要打印列表中所有客户的信息，请使用循环。 用户可以通过多种方式删除客户。您可以从用户那里接收一个整数并删除给定索引处的客户。您还可以接收客户名称并将其与客户名称进行循环比较，然后删除具有收到名称的客户名称。

另外，不要使用空括号。只需在 if 条件前面加上 ! 即可反转它