#30158 [Bgs]: strpos doesn't work as it should

ID: 30158 Updated by: rasmus@php.net Reported By: a dot bendilas at zefxis dot gr Status: Bogus Bug Type: Strings related Operating System: WinXP SP2 PHP Version: 4.3.8 New Comment: No, it means you should do a !== false check. Anything except false means it found it. Previous Comments: ------------------------------------------------------------------------ [2004-09-20 09:12:01] a dot bendilas at zefxis dot gr Apparently the PHP manual isn't so clear on how to use the === operator. So, what it really means is that you should check for something like this: $string = 'time is money'; $srchstring = 'time'; $position = strpos($string, $srchstring); if (($position > 0) || ($position === 0)) echo 'Search string is included in the original string!'; else echo 'Search string is not included in the original string!'; ------------------------------------------------------------------------ [2004-09-20 08:53:42] a dot bendilas at zefxis dot gr A note from the PHP manual on strstr: If you only want to determine if a particular needle occurs within haystack, use the faster and less memory intensive function strpos() instead. A warning from the PHP manual on strpos: This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE, such as 0 or "". Please read the section on Booleans for more information. Use the === operator for testing the return value of this function. As for why I'm doing a check for true, it's because '0' evaluates to false. If my original string was 'time is money' then $position would be 0: Reproduce code: --------------- $string = 'time is money'; $srchstring = 'time'; $position = strpos($string, $srchstring); echo 'String: '.$string.'<br />'; echo 'Search string: '.$srchstring.'<br />'; echo 'Position of search string: '.$position.'<br />'; if ((strpos($string, $srchstring) === true)) echo 'Search string is included in the original string!'; else echo 'Search string is not included in the original string!'; Expected result: ---------------- Search string is included in the original string! Actual result: -------------- String: time is money Search string: time Position of search string: 0 Search string is not included in the original string! ------------------------------------------------------------------------ [2004-09-20 00:18:56] rasmus@php.net Why are you doing a === to true? strpos is clearly documented to return a integer specifying the position in the string on a match or false on a failure. It will never return true. ------------------------------------------------------------------------ [2004-09-19 22:09:19] a dot bendilas at zefxis dot gr Description: ------------ Although strpos returns the position of the needle correctly, when testing the return value with a boolean operator to see if it's true, it produces the opposite result. Reproduce code: --------------- $string = 'Once upon a time in America'; $srchstring = 'time'; $position = strpos($string, $srchstring); echo 'String: '.$string.'<br />'; echo 'Search string: '.$srchstring.'<br />'; echo 'Position of search string: '.$position.'<br />'; if ((strpos($string, $srchstring) === true)) echo 'Search string is included in the original string!'; else echo 'Search string is not included in the original string!'; Expected result: ---------------- Search string is included in the original string! Actual result: -------------- Search string is not included in the original string! ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=30158&edit=1