Question

What is the best way to store an element that has multiple elements? As in a 6d array.
I have seen something along the lines of ArrayList(ArrayList(ArrayList(ArrayList))), but don’t have a clue as to how or mostly why it would be configure as such or how to access the elements!

As an example, I want to create an array(list) that stores the following information:

house id, house number, street name, residents, owner first name, owner last name

I would like to be able to sort and search on anyone of the sub-elements in the main record element.

What I have done is create an arraylist that contains an arraylist for each of these. Basically I have a class called HouseArray that has a method called CreateArray. From my class GUI, I have

houses = new HouseArray();
houses.CreateArray();

In class
HouseArray, my method CreateArray has

ArrayList<Integer> entryID;
ArrayList<Integer> houseNum;
ArrayList<String> streetName;
ArrayList<Integer> residents;
ArrayList<String> firstName;
ArrayList<String> lastName; 

entryID = new ArrayList();
houseNum = new ArrayList();
streetName = new ArrayList();
residents = new ArrayList();
firstName = new ArrayList();
lastName = new ArrayList(); 

and then I use an AddEntry method that puts data into each arraylist.

this.entryID.add(12345);
this.houseNum.add(9876);
this.streetName.add("My Street");
this.residents.add(4);
this.firstName.add("John");
this.lastName.add("Jones");

I am at a loss at how I would be able to sort this mess and keep the entries synchronized without manually writing a lot of coding to do it all. Also, I want to be able to sum the number of residents that live on a particular streetName or total the number of residents that live in houses owned firstName or lastName.

Am I on the right track or is there a better way to do this?
Teaching myself java, so not sure if this counts as homework.

Answer 1

As an example, I want to create an array(list) that stores the
following information:

house id, house number, street name, house color, owner first name,
owner last name

the best approach is to create a Class name it House and have these attributes as its state.

class House {

private long houseId;
private long hNo;
private String streetname;
private String color;
private String owner;
private String firstName;
public House(long houseId, long hNo, String streetName, String color, String owner, String firstName){
  //initialize your instance variables here

}

 public void setHouseId(long houseId){
  this.houseId = houseId;
  }
 //do the same thing for reamining attributes
 //getters and setters for all the attributes.
}

now, create a java.util.List which holds House Object.

List<house> houseList = new Arraylist<>();
//and populate the list with house objects.
House house1 = new House(123,223,"Bond Street", "Green","James Bond", "James");
list.add(house1);

This approach is more Object-Oriented way of doing things, as House represents an Object which has state and behaviour.However, if you want to sort your House elements in your arrayList you will have to override equals and hashcode methods.