note 90767 added to function.empty

When using the php empty() function to check submitted variables such as $_POST or $_GET, be careful to remember that values 0 (integer) and "0" (string with zero character) are all considered empty. eg. in a simple cms a page ID of zero might be used to indicate that the homepage should be displayed but using the following code: <?php if (isset($_GET['pid'] && !empty($_GET['pid']) { // assign value to local variable $pageID = $_GET['pid']; } else { echo "missing variable 'pageID'"; } ?> When attempting to display the homepage using a pid of zero the above code will fail. So as a result i wrote a small function to replace the php empty() function in situations where you want 0 and "0" not to be considered empty. <?php function is_empty($var, $allow_false = false, $allow_ws = false) { if (!isset($var) || is_null($var) || ($allow_ws == false && trim($var) == "" && !is_bool($var)) || ($allow_false === false && is_bool($var) && $var === false) || (is_array($var) && empty($var))) { return true; } else { return false; } } ?> This function will allow you to test a variable is empty and considers the following values as empty: an unset variable -> empty null -> empty 0 -> NOT empty "0" -> NOT empty false -> empty true -> NOT empty 'string value' -> NOT empty " " (white space) -> empty array() (empty array) -> empty There are two optional parameters: $allow_false: setting this to true will make the function consider a boolean value of false as NOT empty. This parameter is false by default. $allow_ws: setting this to true will make the function consider a string with nothing but white space as NOT empty. This parameter is false by default. In Testing: <?php // an unset variable echo 'unset variable ($notset) - Empty: '; echo is_empty($notset) ? 'yes<br />' : 'no<br />'; // NULL variable echo 'null - Empty: '; $var = null; echo is_empty($var) ? 'yes<br />' : 'no<br />'; // integer 0 echo '0 - Empty: '; $var = 0; echo is_empty($var) ? 'yes<br />' : 'no<br />'; // string "0" echo 'string "0" - Empty: '; $var = "0"; echo is_empty($var) ? 'yes<br />' : 'no<br />'; // boolean value false echo 'false - Empty: '; $var = false; echo is_empty($var) ? 'yes<br />' : 'no<br />'; // allow boolean value false echo 'false ($allow_false = true) - Empty: '; $var = false; echo is_empty($var, true) ? 'yes<br />' : 'no<br />'; // boolean value true echo 'true - Empty: '; $var = true; echo is_empty($var) ? 'yes<br />' : 'no<br />'; // string echo 'string "foo" - Empty: '; $var = "foo"; echo is_empty($var) ? 'yes<br />' : 'no<br />'; // white space echo 'white space " " - Empty: '; $var = " "; echo is_empty($var) ? 'yes<br />' : 'no<br />'; // allow white space echo 'white space ($allow_ws = true) " " - Empty: '; $var = " "; echo is_empty($var, false, true) ? 'yes<br />' : 'no<br />'; // empty array echo 'empty array - Empty: '; $var = array(); echo is_empty($var) ? 'yes<br />' : 'no<br />'; ?> the above code outputs the following: unset variable ($notset) - Empty: yes null - Empty: yes 0 - Empty: no string "0" - Empty: no false - Empty: yes false ($allow_false = true) - Empty: no true - Empty: no string "foo" - Empty: no white space " " - Empty: yes white space ($allow_ws = true) " " - Empty: no empty array - Empty: yes Hope this code is useful for someone. Michael ---- Server IP: 92.48.74.199 Probable Submitter: 86.7.12.43 ---- Manual Page -- http://www.php.net/manual/en/function.empty.php Edit -- https://master.php.net/note/edit/90767 Del: integrated -- https://master.php.net/note/delete/90767/integrated Del: useless -- https://master.php.net/note/delete/90767/useless Del: bad code -- https://master.php.net/note/delete/90767/bad+code Del: spam -- https://master.php.net/note/delete/90767/spam Del: non-english -- https://master.php.net/note/delete/90767/non-english Del: in docs -- https://master.php.net/note/delete/90767/in+docs Del: other reasons-- https://master.php.net/note/delete/90767 Reject -- https://master.php.net/note/reject/90767 Search -- https://master.php.net/manage/user-notes.php