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Re: Evaluate a string as a variable name [message #70729 is a reply to message #70723]

Mon, 03 May 2010 15:24

Michael Galloy
Messages: 1114
Registered: April 2006

Senior Member

On 5/3/10 4:02 PM, laurel wrote:
> I have a structure that has multiple name/value pairs, and I want to
> extract the value that corresponds with the name. However, I am only
> passing in a string of the name, not the structure.name, so I need a
> way to combine the two such that I am evaluating the string. It might
> be easier to explain with an example:
>
> ***
> ;create a simple structure
> struct={name1:9, $
> name2:5, $
> name3:1}
>
> ;variable that matches the part of the structure I want
> x='name2'
>
> ;create a string that if it were a variable, it would be part of the
> structure, 'struct.name2'
> y='struct'+'.'+x
>
> ;want to have z=5, or z=struct.name2 rather than z='struct.name2'
> ;Here evaluate stands in for whatever I would do to make that happen
> z=evaluate(y)
> ***
>
> Does anyone know how to make z equal to the value corresponding with
> struct.name2?

How about this:

x = 'name2'
struct = { name1:9, $
name2:5, $
name3:1 }
names = tag_names(struct)
ind = where(strupcase(x) eq names, count)
if (count gt 0L) then z = struct.(ind[0])

Mike
--
www.michaelgalloy.com
Research Mathematician
Tech-X Corporation

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[Message index]

		Re: Evaluate a string as a variable name By: laurel on Tue, 04 May 2010 07:48
		Re: Evaluate a string as a variable name By: Michael Galloy on Mon, 03 May 2010 15:24
		Re: Evaluate a string as a variable name By: Craig Markwardt on Tue, 04 May 2010 19:31

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