Do I need two new List<ParentDetail>() constructors?

I have the following class called Parent. It contains a list of ParentDetail classes:

public class Parent
{

    public Parent()
    {
       this._parentDetails = new List<ParentDetail>();
    }

    public IList<ParentDetail> ParentDetails
    {
        get { return _parentDetails; }
    }

    private List<ParentDetail> _parentDetails = 开发者_开发问答new List<ParentDetail>();

}

public class ParentDetail
{
    public string FileName { get; set; }
}

The class seems to work but I don't understand why "= new List();" appears twice. Can someone explain in a couple of lines what is happening?

---

Do I need two new List() constructors?

No, one of them would be enough - creating two instaces of which one will never be used is superfluous.

---

This is redundancy, which is not needed. Either one of them can be removed.

---

How about this

private List<ParentDetail> _parentDetails;
public Parent()
{
   this._parentDetails = new List<ParentDetail>();
}

Excellent explanation Here

---

It doesn't have to, and shouldn't. In this case _parentDetails is initialised twice.

Both the assignments are equivalent in this case. For what it's worth I prefer initiailising in the default constructor, not the field/member declaration.

---

I dont think the inline creation of new List<ParentDetail>(); is needed as it is already done inside your constructor..Or else you can remove the constructor as a whole...

The inline code when compiled creates a default constructor and moves that piece of code inside the constructor.