Bug #64415 [Opn->Nab]: Incorrect conversion between float and int

Edit report at https://bugs.php.net/bug.php?id=64415&edit=1 ID: 64415 Updated by: aharvey@php.net Reported by: bb at codepoet dot de Summary: Incorrect conversion between float and int -Status: Open +Status: Not a bug Type: Bug Package: Variables related Operating System: Debian, Ubuntu, OSX PHP Version: 5.4.12 Block user comment: N Private report: N 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://www.floating-point-gui.de/ Thank you for your interest in PHP. PHP's precision option is obscuring that the double value is actually 1998.9999... — you can see this more clearly at http://codepad.viper-7.com/rRWuzg Previous Comments: ------------------------------------------------------------------------ [2013-03-12 18:44:48] bb at codepoet dot de Description: ------------ If I multiply 19.99 with 100 and cast it to int, I expect a value of 1999, but I get 1998. I verified this on 5 different php 5.4 installations on Mac OSX 10.8.2, Debian and Ubuntu. Test script: --------------- <?php var_dump('TEST #1'); var_dump($x = floatval(19.99 * 100)); var_dump($x = intval($x)); var_dump('TEST #2'); var_dump($x = floatval(1999)); var_dump($x = intval($x)); Expected result: ---------------- string(7) "TEST #1" double(1999) int(1999) Actual result: -------------- string(7) "TEST #2" double(1999) int(1998) ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=64415&edit=1