String conversion from an Object in VB.NET

microsoft.public.dotnet.framework

4 Jan 2005 2:23 PM

Marlon

Which statement gives better performance (where obj can contain any of the
CLR runtime types)

1) CStr(obj)

or

2) obj.ToString()

4 Jan 2005 3:09 PM

Nick Malik [Microsoft]

They are essentially the same. CStr(obj) will generate a bit more IL code
than obj.ToString() because it is a call to a function that will turn around
and call ToString anyway.

If you are interested in performance, this article may help:
http://accessvbsql.advisor.com/doc/12798

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--- Nick Malik [Microsoft]
    MCSD, CFPS, Certified Scrummaster
    http://blogs.msdn.com/nickmalik

Disclaimer: Opinions expressed in this forum are my own, and not
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   I do not answer questions on behalf of my employer. I'm just a
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"Marlon" <yardi4life@online.nospam> wrote in message
news:%23xK2tjm8EHA.3416@TK2MSFTNGP09.phx.gbl...
> Which statement gives better performance (where obj can contain any of the
> CLR runtime types)
>
>
> 1) CStr(obj)
>
> or
>
> 2) obj.ToString()
>
>

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5 Jan 2005 3:44 AM

Steven Cheng[MSFT]

Hi Marlon,

From a general view, I always think call obj(or other class's ) ToString
will be better if there is no particular requirement ot use any Convert
class to do the same task. And as for the CStr, this is a visualbasic
compatible expression which is actually translated to the following call at
runtime:

Microsoft.VisualBasic.CompilerServices.StringType.FromObject(Object value)
in microsoft.visualbasic.dll

And the StringType.FromObject will also do a switch list to compare the
object's Typecode and do the convertion. So I think directly use ToString()
method is always the preferred way.
Do you think so?

thanks.

Regards,

Steven Cheng
Microsoft Online Support

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