Question

I have a c# question that im struggling with. I am designing a class but im not familiar with oop too much. Is it possible to define a list of the same type as the type of the class itself? For example say i have a dog class:

public class Dog
{
    public string _name {get; set;};

    public Dog (string, name)
    {
        _name = name;
    }

    public List<Dog> listOfDogs ()
    {
        // blah blah
    }
}

Is such a structure possible? if so, how? Is it the proper way to do something like this? Or should i create another helper class that simply does the building of the list of dogs by creating separate dog objects?

Thanks

Answer 1

Short answert: Yes, it is.

This makes sense in many cases. A Dog could be associated to other dogs in an OOP world.

Besides, let me just suggest you a few other tiny improvements:

public class Dog
{
  public string Name { get; set; } // PascalCase is a convention here

  public Dog(string name)
  {
    Name = name;
  }

  public IList<Dog> listOfDogs () // try to expose interfaces whenever possible
  {
    // blah blah
  }
}

Especially the interface thing is worth a lot of reading if you are new to OOP. There are a few different list implementations, and OOP helps you to hide these so-called “implementation details”. Later on you could use a Dog[] instead of a List<Dog> without changing consumers of your class. Both do implement IList<Dog>.

It’s stuff that is described in detail in many places. There are books, articles, or this question on SO: What do programmers mean when they say, "Code against an interface, not an object."?