does c# have an eval method?

[Will]

in javascript or the like, when you wish to evaluate a
string you use eval() for instance if you had five text
boxes named textbox1, textbox2, etc. you would write
something like:

for (x=1;x<5;x++) {
eval(textbox + x).text = "item: " + x;
}


how can you do a similar thing in C#? I cannot believe
that there is no eval method. That would just be
rediculous. Thanks in advance for help! :)


Will

[Marina]

Re: does c# have an eval method?

No, there is not.

99% of the time you can code around it - and this type of coding is usually
more efficient anyway.

"Will" <wswelch@comcas t.net> wrote in message
news:033801c394 ea$ca83a8b0$a30 1280a@phx.gbl.. .[color=blue]
> in javascript or the like, when you wish to evaluate a
> string you use eval() for instance if you had five text
> boxes named textbox1, textbox2, etc. you would write
> something like:
>
> for (x=1;x<5;x++) {
> eval(textbox + x).text = "item: " + x;
> }
>
>
> how can you do a similar thing in C#? I cannot believe
> that there is no eval method. That would just be
> rediculous. Thanks in advance for help! :)
>
>
> Will[/color]

[Steve C. Orr [MVP, MCSD]]

Re: does c# have an eval method?

You should be able to use reflection to do this.

Here's an example:

http://www.codeproject.com/useritems/evaluator.asp

--
I hope this helps,
Steve C. Orr, MCSD, MVP

http://Steve.Orr.net

Hire top-notch developers at http://www.able-consulting.com



"Will" <wswelch@comcas t.net> wrote in message
news:033801c394 ea$ca83a8b0$a30 1280a@phx.gbl.. .[color=blue]
> in javascript or the like, when you wish to evaluate a
> string you use eval() for instance if you had five text
> boxes named textbox1, textbox2, etc. you would write
> something like:
>
> for (x=1;x<5;x++) {
> eval(textbox + x).text = "item: " + x;
> }
>
>
> how can you do a similar thing in C#? I cannot believe
> that there is no eval method. That would just be
> rediculous. Thanks in advance for help! :)
>
>
> Will[/color]

[Rick Strahl [MVP]]

Re: does c# have an eval method?


No there's no eval method unfortunately but you can use Reflection in most
cases to evaluate property expressions or call expressions on objects
dynamically.

eval(textbox + x).text = "item: " + x;

Here's one of the wrappers I use for this sort of thing:

public const BindingFlags MemberAccess =
BindingFlags.Pu blic | BindingFlags.No nPublic |
BindingFlags.St atic | BindingFlags.In stance | BindingFlags.Ig noreCase ;

public static object GetField(object loObject,string lcProperty)
{
return
loObject.GetTyp e().GetField(lc Property,wwUtil s.MemberAccess) .GetValue(loObj e
ct);
}
public static void SetField(object loObject,string lcProperty,obje ct
loValue)
{

loObject.GetTyp e().GetField(lc Property,wwUtil s.MemberAccess) .SetValue(loObj e
ct,loValue);
}

You can then call this like so:

(TextBox) tb = wwUtils.GetFiel d(this,"textbox " + x);
string text = tb.Text;

This works as long as the the field or property in question is not marked as
Private as reflection requires external visibility in order to get at the
types. The same sort of thing works for Properties...

Hope this helps,

+++ Rick ---

--

Rick Strahl
West Wind Technologies

http://www.west-wind.com/

http://www.west-wind.com/wwHelp

----------------------------------
Making waves on the Web


"Will" <wswelch@comcas t.net> wrote in message
news:033801c394 ea$ca83a8b0$a30 1280a@phx.gbl.. .[color=blue]
> in javascript or the like, when you wish to evaluate a
> string you use eval() for instance if you had five text
> boxes named textbox1, textbox2, etc. you would write
> something like:
>
> for (x=1;x<5;x++) {
> eval(textbox + x).text = "item: " + x;
> }
>
>
> how can you do a similar thing in C#? I cannot believe
> that there is no eval method. That would just be
> rediculous. Thanks in advance for help! :)
>
>
> Will[/color]

[John Timney \(Microsoft MVP\)]

Re: does c# have an eval method?

jscript has one, you could always import the approapriate jscript lib and
use that

--
Regards

John Timney (Microsoft ASP.NET MVP)
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ISBN:1-861007-91-4
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Professional JSP 2nd Edition
ISBN: 1861004958
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Beginning JSP Web Development
ISBN: 1861002092
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----------------------------------------------

"Will" <wswelch@comcas t.net> wrote in message
news:033801c394 ea$ca83a8b0$a30 1280a@phx.gbl.. .[color=blue]
> in javascript or the like, when you wish to evaluate a
> string you use eval() for instance if you had five text
> boxes named textbox1, textbox2, etc. you would write
> something like:
>
> for (x=1;x<5;x++) {
> eval(textbox + x).text = "item: " + x;
> }
>
>
> how can you do a similar thing in C#? I cannot believe
> that there is no eval method. That would just be
> rediculous. Thanks in advance for help! :)
>
>
> Will[/color]