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

Steve Dondley sdondley at gmail.com
Fri Oct 14 12:20:05 UTC 2005

> It is well known that these are not the same.
> http://www.php.net/manual/en/types.comparisons.php

These are GREAT charts.  Duly bookmarked.

> We have already found that is_null is slower but equals to === NULL so use
> the latter. In the table referenced above !isset always equals to is_null,
> so I propose to use !isset when we want to check for, well, not being set.
> if ($foo) and if (isset($foo)) is not the same, often it's a shorthand for
> if(isset($foo) && $foo != 0). I think if(isset($foo) && $foo) will always
> do. Sometimes isset() can be ommited because we know $foo is set.
> Regards
> NK

Dondley Communications

Communicate or Die: American Labor Unions and the Internet

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