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

[Steve Dondley]

I was thinking, this problem also stems from the fact that sometimes
fields have a NULL value in the database and sometimes are stored as
empty strings.  We will probably want to settle on a way of storing
string in the database, too.

On 10/13/05, Nedjo Rogers <nedjo at gworks.ca> 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!
>
>


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