Is it better to use Enumerable.Empty() as opposed to new List() to initialize an IEnumerable?

Question

Suppose you have a class Person :

public class Person
{
   public string Name { get; set;}
   public IEnumerable Roles {get; set;}
}
         


        

Answer 1

The typical problem with exposing the private List as an IEnumerable is that the client of your class can mess with it by casting. This code would work:

  var p = new Person();
  List roles = p.Roles as List;
  roles.Add(Role.Admin);

You can avoid this by implementing an iterator:

public IEnumerable Roles {
  get {
    foreach (var role in mRoles)
      yield return role;
  }
}