Fwd: strings & expressions in Module
- To: mathgroup at smc.vnet.net
- Subject: [mg6253] Fwd: [mg6244] strings & expressions in Module
- From: BobHanlon at aol.com
- Date: Mon, 3 Mar 1997 01:29:06 -0500
- Sender: owner-wri-mathgroup at wolfram.com
Either of the following:
Module[{y = 99}, Evaluate[ToExpression["y"]]]
99
Module[{y}, y = 99; Evaluate[ToExpression[
"y$" <> ToString[$ModuleNumber-1]]]]
99
---------------------
Forwarded message:
From: murray at math.umass.edu (Murray Eisenberg)
To: mathgroup at smc.vnet.net
To: mathgroup at smc.vnet.net
Naively, I expect the following, when evaluated, to return result 99:
Module[{y},
y = 99;
Evaluate at ToExpression["y"]
]
But it doesn't; instead, it returns:
y
I suspect the problem is that, inside the Module, y is not really y
but rather y$1 or some symbol of the kind. How can I modify the
string "y" so that, in fact, the result returned is the value 99
stored into y?
(Yes, this likes a strange thing to do: assign a value to a symbol
inside a Module and then try to refer to the symbol indirectly by a
string giving its name. There's a good reason I want to do this!)
--
Murray Eisenberg Internet: murray at math.umass.edu
Mathematics & Statistics Dept. Voice: 413-545-2859 (W)
University of Massachusetts 413-549-1020 (H)
Amherst, MA 01003 Fax: 413-545-1801