Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Programming > ASP .Net > ASP General > Dynamic Variable Names - Syntax?

Reply
Thread Tools

Dynamic Variable Names - Syntax?

 
 
Ken Halley
Guest
Posts: n/a
 
      11-06-2003
How does one refer to a variable name using a variable within a variable
name??? For example, I want to perform a SQL query and use the results of
the query to determine which variable to assign a value to. Let's say I've
dimmed 12 variables based on the months called "featured_x_product" where x
is the month. I'd like to refer to the variable with something
like: featured_" & R("month") & "_product where R("month") is the from the
current row in the db. I don't know the correct syntax or method for doing
so. A full example is provided below. Thanks in advance for you help!

dim featured_jan_product
dim featured_feb_product
dim featured_mar_product
dim featured_apr_product
....

SELECT status, month from products where year='2004' AND
page='featured_products'

While not R.EOF
If R("status") = "sold" Then
featured_" & R("month") & "_product = "Sold Out!" // (choose the
variable based on the "month" value in the current row)
Else
featured_" & R("month") & "_product = "Buy Now!"
End If
R.MoveNext
Wend




 
Reply With Quote
 
 
 
 
Aaron Bertrand - MVP
Guest
Posts: n/a
 
      11-06-2003
Take a look at eval and exec in the VBScript documentation.



"Ken Halley" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> How does one refer to a variable name using a variable within a variable
> name??? For example, I want to perform a SQL query and use the results of
> the query to determine which variable to assign a value to. Let's say

I've
> dimmed 12 variables based on the months called "featured_x_product" where

x
> is the month. I'd like to refer to the variable with something
> like: featured_" & R("month") & "_product where R("month") is the from the
> current row in the db. I don't know the correct syntax or method for

doing
> so. A full example is provided below. Thanks in advance for you help!
>
> dim featured_jan_product
> dim featured_feb_product
> dim featured_mar_product
> dim featured_apr_product
> ...
>
> SELECT status, month from products where year='2004' AND
> page='featured_products'
>
> While not R.EOF
> If R("status") = "sold" Then
> featured_" & R("month") & "_product = "Sold Out!" // (choose the
> variable based on the "month" value in the current row)
> Else
> featured_" & R("month") & "_product = "Buy Now!"
> End If
> R.MoveNext
> Wend
>
>
>
>



 
Reply With Quote
 
 
 
 
Ray at
Guest
Posts: n/a
 
      11-06-2003
You can use the Eval function to do this, but I suggest not using Eval. It
makes for the most confusing and sloppy code you'll ever see.

How about using an array?

Dim featured_products(11) ''vbscrip arrays are zero based

If your storing your months in your database as "jan", "feb", "mar", and so
on, you'll have to deal with them with a select Case or some other thing.
Or, use a dictionary object or something. Let's try with a dictionary
object first.

Dim oDict
oDict.Add "jan", 0
oDict.Add "feb", 1
oDict.Add "mar", 2
oDict.Add "apr", 3
oDict.Add "may", 4
oDict.Add "jun", 5
oDict.Add "jul", 6
oDict.Add "aug", 7
oDict.Add "sep", 8
oDict.Add "oct", 9
oDict.Add "nov", 10
oDict.Add "dec", 11


While Not r.EOF
If r("status") = "sold" Then
featured_products(oDict(r("month"))) = "Sold out"
Else
''''etc.


My mind has been sleeping all week, so if this makes no sense or if I make
no sense, accept my apologies.

Ray at work





"Ken Halley" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> How does one refer to a variable name using a variable within a variable
> name??? For example, I want to perform a SQL query and use the results of
> the query to determine which variable to assign a value to. Let's say

I've
> dimmed 12 variables based on the months called "featured_x_product" where

x
> is the month. I'd like to refer to the variable with something
> like: featured_" & R("month") & "_product where R("month") is the from the
> current row in the db. I don't know the correct syntax or method for

doing
> so. A full example is provided below. Thanks in advance for you help!
>
> dim featured_jan_product
> dim featured_feb_product
> dim featured_mar_product
> dim featured_apr_product
> ...
>
> SELECT status, month from products where year='2004' AND
> page='featured_products'
>
> While not R.EOF
> If R("status") = "sold" Then
> featured_" & R("month") & "_product = "Sold Out!" // (choose the
> variable based on the "month" value in the current row)
> Else
> featured_" & R("month") & "_product = "Buy Now!"
> End If
> R.MoveNext
> Wend
>
>
>
>



 
Reply With Quote
 
Ken Halley
Guest
Posts: n/a
 
      11-07-2003
Thanks Ray. The situation is a little more complicated than my example in
that I have two pieces of the variable name that I want to make dynamic, the
month and the category (see below). So the single array idea doesn't solve
it. Any other thoughts?

The variable format is: category_month_color

R("category") & "_" & R("month") & "_color = "#0000FF"



"Ray at <%=sLocation%>" <myfirstname at lane34 dot com> wrote in message
news:(E-Mail Removed)...
> You can use the Eval function to do this, but I suggest not using Eval.

It
> makes for the most confusing and sloppy code you'll ever see.
>
> How about using an array?
>
> Dim featured_products(11) ''vbscrip arrays are zero based
>
> If your storing your months in your database as "jan", "feb", "mar", and

so
> on, you'll have to deal with them with a select Case or some other thing.
> Or, use a dictionary object or something. Let's try with a dictionary
> object first.
>
> Dim oDict
> oDict.Add "jan", 0
> oDict.Add "feb", 1
> oDict.Add "mar", 2
> oDict.Add "apr", 3
> oDict.Add "may", 4
> oDict.Add "jun", 5
> oDict.Add "jul", 6
> oDict.Add "aug", 7
> oDict.Add "sep", 8
> oDict.Add "oct", 9
> oDict.Add "nov", 10
> oDict.Add "dec", 11
>
>
> While Not r.EOF
> If r("status") = "sold" Then
> featured_products(oDict(r("month"))) = "Sold out"
> Else
> ''''etc.
>
>
> My mind has been sleeping all week, so if this makes no sense or if I make
> no sense, accept my apologies.
>
> Ray at work
>
>
>
>
>
> "Ken Halley" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
> > How does one refer to a variable name using a variable within a variable
> > name??? For example, I want to perform a SQL query and use the results

of
> > the query to determine which variable to assign a value to. Let's say

> I've
> > dimmed 12 variables based on the months called "featured_x_product"

where
> x
> > is the month. I'd like to refer to the variable with something
> > like: featured_" & R("month") & "_product where R("month") is the from

the
> > current row in the db. I don't know the correct syntax or method for

> doing
> > so. A full example is provided below. Thanks in advance for you help!
> >
> > dim featured_jan_product
> > dim featured_feb_product
> > dim featured_mar_product
> > dim featured_apr_product
> > ...
> >
> > SELECT status, month from products where year='2004' AND
> > page='featured_products'
> >
> > While not R.EOF
> > If R("status") = "sold" Then
> > featured_" & R("month") & "_product = "Sold Out!" // (choose

the
> > variable based on the "month" value in the current row)
> > Else
> > featured_" & R("month") & "_product = "Buy Now!"
> > End If
> > R.MoveNext
> > Wend
> >
> >
> >
> >

>
>



 
Reply With Quote
 
Aaron Bertrand - MVP
Guest
Posts: n/a
 
      11-07-2003
> month and the category (see below). So the single array idea doesn't
solve
> it. Any other thoughts?


Uh, a two dimensional array?

dim arrayName(<<<?>>>, 2)
arrayName(0, 0) = R("category")
arrayName(0, 1) = R("month")
arrayName(0, 2) = "#0000FF"

Dictionary objects can also hold complex types like arrays or even other
dictionary objects. I really think others are on the right track when they
suggest staying away from eval/exec... I just offered it as a possible
alternative.


 
Reply With Quote
 
Ray at
Guest
Posts: n/a
 
      11-07-2003
I strongly suggest you find another approach that involves arrays or
something else. If you write a page that is laden with Evals and Execs,
it's going to be impossible to understand a week later when you look at it.
This is just my opinion.

Ray at home

"Ken Halley" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Thanks Ray. The situation is a little more complicated than my example in
> that I have two pieces of the variable name that I want to make dynamic,

the
> month and the category (see below). So the single array idea doesn't

solve
> it. Any other thoughts?
>
> The variable format is: category_month_color
>
> R("category") & "_" & R("month") & "_color = "#0000FF"
>



 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Dynamic variable names without EVAL - NEWBIE jason@cyberpine.com ASP .Net 2 07-15-2010 02:39 PM
Re: Dynamic variable names Steve Holden Python 0 02-07-2010 01:31 PM
dynamic variable names or using a variable as another's name Peter Buckley Ruby 5 02-27-2009 06:05 PM
checking for mis-spelled variable names / function names News123 Python 2 11-26-2008 12:37 AM
confusion between global names and instantiated object variable names wanwan Python 3 10-14-2005 09:46 PM



Advertisments