note 13254 deleted from function.isset by didou

Note Submitter: chris@owta.net ---- An example of how to and how not to check if form elements are empty: <? if ($HTTP_POST_VARS) { $a = $HTTP_POST_VARS['element']; // Wrong if (!$a) { echo "if(!\$a) true<br>"; } // Right if (!isset($a)) { echo "if (!isset(\$a)) true<br>"; } // Wrong if (empty($a)) { echo "if (empty(\$a)) true<br>"; } echo "contents of 'element' field:".$a; } ?> -- In other words always use isset! Try this out with a form and enter "0". Maybe it's blindingly obvious to most, but caused me many a headache until i realised i should be using isset for strings, and not !$stringVar, a feature which could be said to be a weakness of php, as it encourages bad practice.