[thelist] PH isset and is_empty
Steve Lewis
nepolon at worlddomination.net
Thu Jul 3 14:04:03 CDT 2003
fstorr wrote:
>I'm trying to do some basic PHP form validatation. I'm passing a
>variable through the the form processing page and picking it up fine
>
>
>the user has entered nothing (I know that I can just do if (!$var) but I
>want to explore further).
>
>Looking at the manual, it seems the following should work:
>If (isset($var))
>But if I type in nothing, it still returns true, which I don't
>
>
--isset($var) will tell you if the name "var" is a defined variable.
--(!$var) will tell you if the value of the variable "var" has a "false"
(false is defined as any of { 0, null, the empty string aka "" ) value.
Technically, you should do both,
if (!isset($var) || (!$var))
// than the user has entered nothing
to determine if the user has entered something because you cannot depend
on the client to send an empty value on a form submit. Checkboxes are
only sent if they are checked, and the spec says that regardless of
type, inputs need not send anything if they are not set.
<tip>
you could embed this logic into a handy function!
function fieldnotset($var)
{
return (!isset($var) || (!$var));
}
[...]
if fieldnotset($var) {
// user left the field blank
}
</tip>
More information about the thelist
mailing list