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Groups > comp.lang.javascript > #13336

Re: How to Pass variable name to a function

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Stan Weiss schrieb:
> save(stanForm.VD.value, AInput, 'Valve Diameter')"
>
> function save( field, vary, text ) {
>       if( isNaN( field ) )
>       {
>          alert( text + " is not numeric" );
>       }
>       else
>       {
>           AInput = eval(field);  // this Works
>           vary = eval(field);    // this does not workWorks
>       }
> }
>
> Can anyone see what I am doing wrong?

JavaScript does not have call-by-reference. Instead of passing a 
reference to the variable where the result should be stored, you pass 
the actual value of AInput to the function, where it gets the value of 
the local variable "vary". By assigning the result to vary, vary will 
get a new value. AInput is forgotten.

Also, you seem to try to parse a number with eval. Urghh. Use 
parseFloat() instead.

So, your code should be:

function numeric(field, fallback, name) {
     var num = parseFloat(field);
     if (isNaN(num)) {
         alert(name + " is not numeric");
         return fallback;
     } else
         return num;
}
AInput = numeric(stanForm.VD.value, AInput, 'Valve Diameter');

regards,
  Bergi

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How to Pass variable name to a function Stan Weiss <srweiss@erols.com> - 2012-04-11 12:26 -0400
  Re: How to Pass variable name to a function Andreas Bergmaier <andber93@web.de> - 2012-04-11 19:47 +0200
    Re: How to Pass variable name to a function Stan Weiss <srweiss@erols.com> - 2012-04-11 14:21 -0400
      Re: How to Pass variable name to a function Stefan Weiss <krewecherl@gmail.com> - 2012-04-11 20:53 +0200
        Re: How to Pass variable name to a function Stan Weiss <srweiss@erols.com> - 2012-04-11 15:16 -0400
          Re: How to Pass variable name to a function Gene Wirchenko <genew@ocis.net> - 2012-04-11 15:18 -0700
  Re: How to Pass variable name to a function "Evertjan." <exjxw.hannivoort@interxnl.net> - 2012-04-11 21:20 +0000
  Re: How to Pass variable name to a function Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-04-11 23:56 +0200
    Re: How to Pass variable name to a function Stan Weiss <srweiss@erols.com> - 2012-04-12 00:48 -0400
      Re: How to Pass variable name to a function Andrew Poulos <ap_prog@hotmail.com> - 2012-04-12 15:21 +1000
        Re: How to Pass variable name to a function Stan Weiss <srweiss@erols.com> - 2012-04-12 02:11 -0400
          Re: How to Pass variable name to a function Andrew Poulos <ap_prog@hotmail.com> - 2012-04-12 18:57 +1000
            Re: How to Pass variable name to a function Stan Weiss <srweiss@erols.com> - 2012-04-12 09:35 -0400
      Re: How to Pass variable name to a function Stefan Weiss <krewecherl@gmail.com> - 2012-04-12 08:08 +0200
        Re: How to Pass variable name to a function Stan Weiss <srweiss@erols.com> - 2012-04-12 10:13 -0400
      Re: How to Pass variable name to a function Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-04-12 22:47 +0200
        Re: How to Pass variable name to a function Stan Weiss <srweiss@erols.com> - 2012-04-12 17:04 -0400
          Re: How to Pass variable name to a function Tim Streater <timstreater@greenbee.net> - 2012-04-12 22:17 +0100
          Re: How to Pass variable name to a function Scott Sauyet <scott.sauyet@gmail.com> - 2012-04-13 05:13 -0700
            Re: How to Pass variable name to a function "Evertjan." <exjxw.hannivoort@interxnl.net> - 2012-04-13 16:27 +0000
              Re: How to Pass variable name to a function Scott Sauyet <scott.sauyet@gmail.com> - 2012-04-16 04:11 -0700
        Re: How to Pass variable name to a function "Tom de Neef" <tdeneef@qolor.nl> - 2012-04-12 23:34 +0200
          Re: How to Pass variable name to a function Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2012-04-13 10:03 +0200
          Re: How to Pass variable name to a function Erwin Moller <erwinmollerusenet@xs4all.nl> - 2012-04-13 12:03 +0200
            Re: How to Pass variable name to a function Andrew Poulos <ap_prog@hotmail.com> - 2012-04-13 21:35 +1000
            Re: How to Pass variable name to a function Gene Wirchenko <genew@ocis.net> - 2012-04-13 09:00 -0700
  Re: How to Pass variable name to a function Stan Weiss <srweiss@erols.com> - 2012-04-12 14:03 -0400
  Re: How to Pass variable name to a function Dr J R Stockton <reply1215@merlyn.demon.co.uk.not.invalid> - 2012-04-12 20:06 +0100
    Re: How to Pass variable name to a function Stan Weiss <srweiss@erols.com> - 2012-04-12 18:54 -0400

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