#42812 [Opn->Bgs]: integer value returned by php incorrect

ID: 42812 Updated by: pajoye@php.net Reported By: laurent at polenord dot com -Status: Open +Status: Bogus Bug Type: Scripting Engine problem Operating System: linux PHP Version: 5.2.4 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. NB: remove the (int) cast to see what actually happens. Previous Comments: ------------------------------------------------------------------------ [2007-10-01 10:33:30] laurent at polenord dot com Description: ------------ infact the problem occurs on PHP 5.2.3 I want to simply return a float multiplied by a million, and force it to an integer value to avoid php returns int in weird format (2.9E+06 for example), and it doesn't return the correct value. This is very strange as it seems to occurs only on the '2.09' value : it's ok with 1.09 and 3.09, 2.19, 2.091 and 2.089, etc... Reproduce code: --------------- $cpc = '2.09'; echo $cpc * 1000000; // returns correct value : 2090000 echo "<br/>"; echo (int)($cpc * 1000000); // returns 2089999 !! echo "<br/>"; echo (int)($cpc * 1000 * 1000); // return correct value. Expected result: ---------------- 2090000 2090000 2090000 Actual result: -------------- 2090000 2089999 2090000 ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=42812&edit=1