How do I store an object in ArrayList? [closed]

Question

I'm trying to store an object person in an ArrayList.

I have an ArrayList<String> customer = new ArrayList<String>();

The object 'person' has two variables: name (String) and pNr (long). I have tried to simply add it: customer.add(person) but that doesn't seem to work.

To clarify: I don't want to store the variables individually. I want to store the entire object person in the ArrayList.

I simply can't figure out how to engage this problem or even if it can be done.

Can someone point me in the right direction?

Answer 1

Change your List such that it accepts a Person object instead of a String.

List<Person> customer = new ArrayList<Person>();
Person person = ......;
customer.add(person);

Answer 2

Person Class

public class Person {       
    String name;
    long pNr;    

    public String getName() {
        return name;
    }

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

    public long getPNR() {
        return pNr;
    }

    public void setPNR(long pNr) {
        this.pNr = pNr;
    }   
}

Creating a Person Object

Person person = new Person();
person.setName("Name");
person.setPNR(pNr);

Adding to ArrayList

ArrayList<Person> personList = new ArrayList<Person>();
personList.add(person);

Retrieving Data

String selectedName = personList.get(i).getName();

Answer 3

You need to use a List with a different generic type. Since the generic type specified on your current List is String it will only allow you to add objects of type String into the list.

List<Person> customer = new ArrayList<Person>();

I would also recommend using the List interface in case the need would arise to switch to a different implementation such as LinkedList.

Answer 4

Look at this

import java.util.ArrayList;
import java.util.List;

public class Tester4 {

    public static void main(String args[]) {

        List<Person> persons = new ArrayList<Person>();

        Person person = new Person();
        person.setName("Tester");
        person.setPersonNr(1245L);
        persons.add(person);

        person = new Person();
        person.setName("Tester 2");
        person.setPersonNr(1299L);
        persons.add(person);
    }
}

class Person {

    private String name;

    private Long personNr;

    public String getName() {
        return name;
    }

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

    public Long getPersonNr() {
        return personNr;
    }

    public void setPersonNr(Long personNr) {
        this.personNr = personNr;
    }

}

Answer 5

ArrayList<String> customer = new ArrayList<String>();

in this way you defined that the arrayList customer accept type String only.

ArrayList<Person> customer = new ArrayList<Person>(); 

this will only accept object with Person type (and subType of Person).

Answer 6

define a class Person

public class Person(){
    private String name;
    private long pNr;
    public String getName(){
        return name;
    }
    public void setName(String name){
        this.name = name;
    }
    public long getPNR(){
        return pNr;
    }
    public void setPNR(long pNr){
        this.pNr = pNr;
    }
}

then you use a:

ArrayList<Person> customer = new ArrayList<Person>();