Differences between Private Fields and Private Properties

Question

What is the difference between using Private Properties instead of Private Fields

private String MyValue { get; set; }

// instead of

private String _myValu         


        

Answer 1

Other then what has already been answered, Performance, symantics and completness there is one valid case I have seen for private properties instead of a private field:

public class Item
{
    private Item _parent;
    private List _children;

    public void Add(Item child)
    {
        if (child._parent != null)
        {
            throw new Exception("Child already has a parent");
        }
        _children.Add(child);
        child._parent=this;
    }
}

Let's say that we don't want to expose Parent for whatever reason, but we might also want to do validation checks. Should a parent be able to be added as a child to one of its children?

To resolve this you can make this a property and perform a check for circular references.