Re: zero vs. empty

you could check if the value returned from CGI->param('fieldname') is empty by using the length function

if length($cgi->param('fieldname')) == 0 (that means the field is empt
+y.)
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To check if the value is 0, how about :

  if ($CGI->param('fieldname') == 0)...
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Option 2: if u want to use Javascript, then this might work:

<html
<head>
<script language="Javascript">
function chkinput(objForm) {
 if (objForm.inputfield.value == "") {
     objForm.fld_has_value_or_not.value = "N"
  } else {
     objForm.fld_has_value_or_not.value = "Y"
  }
  objForm.submit();
  return true;

}
</script>
</head>
<body>
<form name="testfrm" method="post" action="cgifile.cgi" onSubmit="retu
+rn chkinput(this);">
<input type=hidden name=fld_has_value_or_not value="">
<input type="text" name="inputfield" value="">
<input type=submit value="Submit">
</form>
</body>
</html>
[download]

in this case, if the input field is empty, the hidden variable will be set to "Y", which can be checked by the cgi file and processed accordingly...
hth...

Comment on Re: zero vs. empty Select or Download Code

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Re: Re: zero vs. empty by Juerd (Abbot) on Mar 03, 2002 at 23:06 UTC
To check if the value is 0, how about : `if ($CGI->param('fieldname') == 0)...` Keep in mind that `"three" == 0`. To check if the entered value equals the single character `0`, use a string comparison: `$something eq '0'`. It's generally a good idea to warn if the user didn't enter nothing or digits. Or, using reversed logic: warn if a non-digit character is found: `die "\$foo contains a non-digit character!\n" if $foo =~ /\D/;` [download] ++ vs lbh qrpbqrq guvf hfvat n ge va Crey :) Nabgure bar vs lbh qvq fb jvgubhg ernqvat n znahny svefg. -- vs lbh hfrq OFQ pnrfne ;) - Whreq	[reply] [d/l] [select]

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Re: Re: zero vs. empty
by Juerd (Abbot) on Mar 03, 2002 at 23:06 UTC

To check if the value is 0, how about : if ($CGI->param('fieldname') == 0)...

Keep in mind that "three" == 0. To check if the entered value equals the single character 0, use a string comparison: $something eq '0'.
It's generally a good idea to warn if the user didn't enter nothing or digits. Or, using reversed logic: warn if a non-digit character is found:

die "\$foo contains a non-digit character!\n" if $foo =~ /\D/;
[download]

++ vs lbh qrpbqrq guvf hfvat n ge va Crey :)
Nabgure bar vs lbh qvq fb jvgubhg ernqvat n znahny svefg.
-- vs lbh hfrq OFQ pnrfne ;)
    - Whreq

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