Bug #417 [Com]: silent (?) change in variable's value behaviour

Edit report at https://bugs.php.net/bug.php?id=417&edit=1 ID: 417 Comment by: hugo at domibay dot es Reported by: jan at nrw dot net Summary: silent (?) change in variable's value behaviour Status: Closed Type: Bug Package: Misbehaving function Operating System: Linux 2.0.33, BSDI 3.1 PHP Version: 3.0 Release Candidate 5 Assigned To: zeev Block user comment: N Private report: N New Comment: This Behaviour still persists in PHP 5.6 on Centos7 I am running constantly into the same problem: The Documentation states on http://php.net/manual/en/function.empty.php The Function empty() would trigger on Values like 0 (0 as an integer) 0.0 (0 as a float) "0" (0 as a string) as empty($var) === true But I found in many cases a String containing a "0" is not empty. It contains a Character that is "0". If I store the Character "0" into a file the file is not empty anymore it contains the text "0". For example: $ echo "0" > myfile.txt On Integers the Value 0 can be a valid number according to the Programming Logic as an Index of an Array for example. The same goes for Float Numbers. I found discarding those Values as "empty" is an Error in most cases of a complex Application. Test script: This Script might be simple but it leads to silent Application Errors that are hard to track down. https://pastebin.com/gjJwHe4T Actual result: The Script will print only: '1' => '2' The other 2 Entries are silently rejected because of the Values "0". Expected result: The Script should print out: '0' => '1' '1' => '2' '3' => '0' On Strings only Values of NULL or "" should trigger empty($var) === true On Integers only Values of NULL should trigger empty($var) === true On Float Numbers only Values of NULL should trigger empty($var) === true Previous Comments: ------------------------------------------------------------------------ [1998-05-29 18:20:11] rasmus Fixed by Zeev ------------------------------------------------------------------------ [1998-05-29 17:54:01] jan at nrw dot net I'm not sure if this is to be called a bug or a feature, but this is the problem i have: - i wrote some apps in PHP3RC4, with excessive use of forms and PHP3-scripts which get form fields POSTed. These scripts contain many value-checks like "if ($form_field1) do something;" this worked like i expected - empty fields in the form resulted in "False" in the above statement. I then upgraded to PHP3RC5 - and now empty form fields result in "True". I realized the new function "empty()" and changed scripts to use this funktion, but now a form-input of "0" results in "empty()=True". This behaviour is against all i'm used to in other scripting languages, i must say. Also, i'm not sure what the intentional use of "empty()" is - a string or Value of "0" isn't an empty variable container for me... or am i totally wrong here? At least, i really would like to know what the intentional behaviour of PHP3/form fields/variables/empty()/if() is or should be. Apart from that - PHP3 becomes better and better! It's a pleasure writing apps for the web with it! thanks for any help/hint, Jan ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=417&edit=1