[drupal-devel] PHP 101: isset() does not check for zero length(empty) strings

Robert Douglass rob at robshouse.net
Fri Oct 14 06:04:36 UTC 2005

/me blushes and admits the same fuzziness.

Nedjo Rogers wrote:
> Awhile back I posted a similar question, see below.  We have a need for 
> some standard guidelines on when to use which test for empty, null, or 
> set variables, arrays, and object properties.
> _______
> I find I'm sometimes not sure which types of test I should apply to test if
> a variable (or array key) is null or empty.
> Looking at the code, I see various usages:
> if (is_null($variable))
> if (empty($variable))
> if ($variable == NULL)
> if ($variable === NULL)
> if ($objectname->propertyname)
> if (array_key_exists($key, $arrayname))
> if ($arrayname['key'])
> etc.
> Can anyone point to or suggest a limited set of tests that we should use,
> and guidelines for when each should be applied?  This would be a useful
> addition to the coding standards, http://drupal.org/node/318.  Thanks!

More information about the drupal-devel mailing list