Difference between a field and a property?

What is the difference between a field and a property in VB.net?





LVL 1
bobinorlandoAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

YZlatCommented:
can you specify what do you mean?
0
CaznaCommented:
A field is simply a variable in which you can store data.  A property on the other hand allows you to execute code when values are either read or written.  This can be usefull for processing user input or for enforcing buisness rules.  Also with a property you can specify it to be either ReadOnly or WriteOnly and prevent the other action from being performed.

Commonly you will use a combination of a private class field and a public property. Something like this:

Private _foo as String

Public Property Foo() As String
    Get
        Return _foo
        'Here you can put code that will execute each time the variable is accessed eg:
        accessCounter += 1
    End Get
    Protected Set(ByVal value As String)
        _foo = value
        'Here you can put some extra code to execute when the variable is set eg:
        isFooSet = True
    End Set
End Property
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
CaznaCommented:
The reason that the field is private and the property is public is to force other classes to access the field through the property so that you know the code in your property is going to be run.
0
bobinorlandoAuthor Commented:
Well,  is it true to say that all variables are fields?

I'm looking for what we used to call the salient anatomical features, or a definition of a field that would distinguish it from all other object types.

For example, can other things be fields (e.g. are properties ever referred to as fields, or do properties have fields, which objects have fields and which don't)?

Or does the use of field overlap and duplicate other vb.net terms for objects and types?
In other words, what are all of the various meanings (other than database meanings which I understand) that "field" is used in vb.net?

Thank you.





0
CaznaCommented:
"Field" is a term more often used by programmers using "C" based languages but in VB.NET it has the same meaning.  In a class you have written it will generally only refer to variables although when accessing other classes say in a DLL some programmers will also refer to properties as fields although I do not find this practice to be accurate.  The origins of the term field was simply as a location to store data so technically a property is not a field as it is only a method of accessing data.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Visual Basic.NET

From novice to tech pro — start learning today.