Question

Following on from this question Good class design by example I have a follow-up one.

I want to create some collections that are owned by other objects. To recap, I have a Person class and I want the Person to be able to have one or more Addresses. So I thought I would create an Address class and an Addresses collection. Make sense? Here’s my code so far

class Person
{
    public Person(int SSN, string firstName, string lastName)
    {
        this.SSN = SSN;
        FirstName = firstName;
        LastName = lastName;
    }

    public int SSN { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

class Address
{
    public Address(string line1, string postCode)
    {
        Line1 = line1;
        PostCode = postCode;
    }

    public int ID { get; set; }
    public string Line1 { get; set; }
    public string PostCode { get; set; }
}

class Addresses : System.Collections.CollectionBase
{
    public int Person { get; set; } // should this be of type Person?

    public void Add(Address addy)
    {
        List.Add(addy);
    }

    public Address Item(int Index)
    {
        return (Address)List[Index];
    }

    public void Remove(int index)
    {
        List.RemoveAt(index);            
    }
}

How can I associate many addresses with a Person? I’d like to do something like this in Main:

Person p = new Person(123,"Marilyn","Manson");
Address a = new Address("Somewhere", "blahblah");
p.Addresses.Add(a);

I then want to be able to save the addresses to a database. Should I do Address.Save() or Addresses.Save() (or something else)?

How would I change my code to implement that? Thanks for looking.

Answer 1

If you want the addresses OWNED by a Person, the person Should include a Collection of Addresses

class Person 
{     
     <all the stuff you have>
     List<Address> Addresses;
}

Don’t forget to new it in the constructor,

Then to add an address you just

Address addressInstance = new Address(){...};
PersonInstance.Addresses.Add( addressInstance );

Cal-