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Re: print variable name and its value

• To: mathgroup at smc.vnet.net
• Subject: [mg99992] Re: print variable name and its value
• From: dh <dh at metrohm.com>
• Date: Thu, 21 May 2009 00:06:58 -0400 (EDT)
• References: <gv0ius$b8v$1@smc.vnet.net>

Hi Karsten,

Mathematica tries to evaluate every expression if possible. By default, 

a function gets bits arguments only after they are evaluated. To prevent 

this, you must specify the attribute HoldAll or HoldFirst.

Further inside the function you muast again take care that the 

expression is not evaluated.

=================================

myVar1 = 1;

myVar2 = 2;

SetAttributes[DumpVars, HoldAll];

DumpVars[d_List] :=

   Function[{x}, Print[HoldForm[x], "= ", x],

     HoldAll] /@ (Unevaluated@d);



DumpVars[{myVar1, myVar2}]



==============================

Daniel



Karsten W. wrote:

> Hello,

> 

> how can I dump out a variable with its value? The following does not

> work:

> 

> myVar1 = 1;

> myVar2 = 2;

> DumpVars[list_List] :=

>   MapThread[(Print[#1, ": ", #2]) &, {Map[ToString[#] &,

>      Unevaluated[list]], list}];

> 

> DumpVar[var_] := Print[ToString[Unevaluated[var]], ":", var];

> 

> 

> DumpVars[{myVar1, myVar2}]

> DumpVar[myVar1]

> 

> Any ideas?

> 

> Kind regards,

> Karsten.

>