[Javascript] Loop problem

[David T. Lovering]

Well, I see a couple of problems...

  In the loop 'for (i=1;i=<%=Numfrm%>;i++)'  you have two equivalence assignments, namely
    i=1 and i=<%=Numfrm%>, where <%Numfrm%> is some variable derived elsewhere.  (Incidently,
  I hope this isn't the real syntax you are using, as <%Numfrm%> will blow up the syntax
  parser inside JavaScript).  If the number of fields is variable and externally defined, a
  much better way of passing it into the function is as follows:

  var Numfrm, form;
  function checkFrm(Numfrm, form) {
    var why ="";
 
    for (var i=1;i<Numfrm;i++) { // it is good practice to pre-declare floating indices as 'var'
      why = checkName(document.form.element[i].value);  // You don't really want to concatenate why //
      if ( why != "") {
        alert(why);
        return false;
      }
    }
  }  // Note that your example was missing a closing brace, and 'form1' wasn't defined //

  I'm only making a wild-ass guess that what you are doing is looking at all the text fields in a form 'form'
  (and they'd better BE text fields, or else the ".value" declaration will crap out), passing them into checkName,
  and if anything other than a null string squirts out, you exit with a false condition.  Incidently, (I'm sure
  you knew this), you don't have a matching 'return true' anywhere in your code.

  The assignment you use, namely 'why += ...' will tack the previous value of the why string onto the front of
  whatever comes back from your checking routine.  Since it dies whenever this is non-null, the concatenation
  is no different than a straight assignment.

  The checking routine is nearly correct, but could do with a minor bit of tweaking:

  var strng;
  function checkName (strng) {
    var return_string = "";
 
    //test of the filling
    if (strng == "") {
      return_string = "you didn't enter a username. \n";
    }
    return return_string;
  } // Note -- 'error' is a reserved token, and shouldn't be used outside its correct context

  This should work more along the lines you expected.

  -- Dave Lovering

  
  
  

Alexandre Zglav wrote:
> 
> Hello all.
> 
> I quite new to javascript and I have a problem with a loop and I just cant
> find a solution to it on the internet.
> 
> I am trying to validate a for m with a variable amount of fields.
> 
> Here is the code i am using :
> 
> <!--
> 
> function CheckForm(form1) {
> 
>         var why ="";
> 
>         for (i=1;i=<%=Numfrm%>;i++)
>                 why += checkName(form1.name[i].value);
>                 if ( why != "") {
>                         alert(why);
>                         return false;
>                 }
> 
> }
> 
> function checkName (strng) {
>         var error = "";
> 
>         //test of the filling
>         if (strng == "") {
>                 error = "you didn' enter a username. \n";
>         }
>         return error;
> }
> 
> 
> -->
> 
> Note that <%=Numfrm%> is a the variable i am retrieving from ASP. It
> returns me an integer value chosen in an earlier field.
> 
> Now my problem is at this point :
> 
> why += checkName(form1.name[i].value);
> 
> It seems that [i] is not accepted as I always get an error at this level
> in my script debugger.
> 
> Can someone help me with this ?
> 
> Thanks in advance.
> 
> Best regards.
> _____________________________________
> IT Projects
> Alexandre Zglav
> Heritage Finance and Trust Company
> 12 cours des bastions
> 1205 Geneva
> Switzerland
> Phone :  ++ 41 22 817 31 68
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