Why not need ref when dataAdapter.Fill

[ad]

Hi,

When we use
myDataAdapter.F ill(myDataTable )

The parameter myDataTable is call by reference.

Why there is no need to add ref before the paremeter?

[Peter Bromberg [C# MVP]]

RE: Why not need ref when dataAdapter.Fil l

"MyDataTabl e" is a reference type. Variables that are reference types consist
of only the pointer to that data. So, when you pass a parameter that is a
reference type into a method, it acts (through the pointer) directly on the
object.
Credit for the quintessential example of clarity in writing on this
difficult subject goes to MVP Jon Skeet in his description here:

http://www.yoda.arachsys.com/csharp/parameters.html

Peter
--
Co-founder, Eggheadcafe.com developer portal:

http://www.eggheadcafe.com

UnBlog:

http://petesbloggerama.blogspot.com

"ad" wrote:
[color=blue]
> Hi,
>
> When we use
> myDataAdapter.F ill(myDataTable )
>
> The parameter myDataTable is call by reference.
>
> Why there is no need to add ref before the paremeter?
>
>
>[/color]

[Truong Hong Thi]

Re: Why not need ref when dataAdapter.Fil l

DataTable is the reference type rather than value type thus the
reference is passed and no need to use ref. It is a compile error if
you add ref here.

[Jon Skeet [C# MVP]]

Re: Why not need ref when dataAdapter.Fil l

ad <flying@wfes.tc c.edu.tw> wrote:[color=blue]
> When we use
> myDataAdapter.F ill(myDataTable )
>
> The parameter myDataTable is call by reference.
>
> Why there is no need to add ref before the paremeter?[/color]

The parameter not passed *by* reference - that means something slightly
different. Instead, the reference (which is the value of the
myDataAdapter variable) is passed by value.

See the page Peter referred you to for more details.

--
Jon Skeet - <skeet@pobox.co m>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too