Best Practice on local use of Private Field x Property

Question

When inside a class you have a private fiels and expose that field on a public property, which one should I use from inside the class?

Below you is an example on what I am trying to find out. Should manioulate the Private Field _Counter or the Property Counter?

Public Class Test

Private _Counter As Integer

Public Property Counter() As Integer
    Get
        Return _Counter
    End Get
    Set(ByVal value As Integer)
        _Counter = value
    End Set
End Property

Private Sub Dosomething()

    'What is the best practice?
    'Direct access to private field or property?

    'On SET
    _Counter += 1
    'OR
    Me.Counter += 1

    'On Get
    Console.WriteLine(_Counter)
    Console.WriteLine(Me.Counter)

End Sub

End Class

Thanks in advance for the help. Edu

Answer 1

In my opinion, using a public accessor internally is over-encapsulation: it blurs the code. With such an approach, otherwise simple operations invoke accessors that may contain more complex logic, so it's harder to analyze the code of the operations.

In my programming experience, I've rarely had a situation when it would help much. Instead, I prefer to access fields directly, and only if it's really needed, to abstract the access by creating a private accessor, which can be used by both the public accessor and other functions. The rationale is that if you need to attach some special logic in the public accessor, chances are that the logic may not be the same for internal access.

Note also that most modern IDEs (like Eclipse) allow to see immediately all references to a private field, and to refactor the code to use a function instead of a direct access.