#36039 [Opn->Bgs]: intVal broken for calculated 1999

ID: 36039 Updated by: tony2001@php.net Reported By: ben at bbbsystems dot net -Status: Open +Status: Bogus Bug Type: *Math Functions Operating System: Free BSD 5.3 PHP Version: 5.1.2 New Comment: Floating point values have a limited precision. Hence a value might not have the same string representation after any processing. That also includes writing a floating point value in your script and directly printing it without any mathematical operations. If you would like to know more about "floats" and what IEEE 754 is read this: http://docs.sun.com/source/806-3568/ncg_goldberg.html Thank you for your interest in PHP. Previous Comments: ------------------------------------------------------------------------ [2006-01-17 01:02:51] ben at bbbsystems dot net The problem also happens with the function floor( ) ------------------------------------------------------------------------ [2006-01-17 00:57:47] ben at bbbsystems dot net Description: ------------ This bug is for the function intVal( ), and I also found that typecasting with (int) produces the same results. This is a very weird bug I encountered because of a price that is 19.99 and our processor requires it to be sent as 1999. 1999 is the only value I was able to find that doesn't work correctly, but I'm sure there are others. I also checked it on a linux system with an older version of php 4 and got the same results. I upgraded our php to 5.1.2 then tried it again after it failed. I suspect the bug to be a floating point issue, but I'm not certain of it. -Ben Laurienti BBB Systems, LLC Reproduce code: --------------- <?php $test1 = intVal(1999); $amount = 19.99 * 100; $test2 = intVal($amount);//value is 1998 $test3 = intVal("$amount");//value is 1999 echo $test1 . "<br />\n"; echo $test2 . "<br />\n"; echo $test3 . "<br />\n"; ?> Expected result: ---------------- 1999 1999 1999 Actual result: -------------- 1999 1998 1999 ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=36039&edit=1