Using a collection initializer
From C# 3, you can use collection initializers to construct a List and populate it using a single expression. The following example constructs a Human and its ContactNumbers:
var human = new Human(1, "Address", "Name") {
ContactNumbers = new List<ContactNumber>() {
new ContactNumber(1),
new ContactNumber(2),
new ContactNumber(3)
}
}
Specializing the Human constructor
You can change the constructor of the Human class to provide a way to populate the ContactNumbers property:
public class Human
{
public Human(int id, string address, string name, IEnumerable<ContactNumber> contactNumbers) : this(id, address, name)
{
ContactNumbers = new List<ContactNumber>(contactNumbers);
}
public Human(int id, string address, string name, params ContactNumber[] contactNumbers) : this(id, address, name)
{
ContactNumbers = new List<ContactNumber>(contactNumbers);
}
}
// Using the first constructor:
List<ContactNumber> numbers = List<ContactNumber>() {
new ContactNumber(1),
new ContactNumber(2),
new ContactNumber(3)
};
var human = new Human(1, "Address", "Name", numbers);
// Using the second constructor:
var human = new Human(1, "Address", "Name",
new ContactNumber(1),
new ContactNumber(2),
new ContactNumber(3)
);
Bottom line
Which alternative is a best practice? Or at least a good practice? You judge it! IMO, the best practice is to write the program as clearly as possible to anyone who has to read it. Using the collection initializer is a winner for me, in this case. With much less code, it can do almost the same things as the alternatives -- at least, the alternatives I gave...