Bug #52415 [Opn->Bgs]: Round Off Error

Edit report at http://bugs.php.net/bug.php?id=52415&edit=1 ID: 52415 Updated by: aharvey@php.net Reported by: benjamin at aceinformatique dot com Summary: Round Off Error -Status: Open +Status: Bogus Type: Bug Package: *General Issues Operating System: Windows PHP Version: 5.2.14 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: ------------------------------------------------------------------------ [2010-07-23 12:36:18] benjamin at aceinformatique dot com Description: ------------ There are a round off problems with add/sub of floating values for instance 0.27+0.34 is not equal to 0.61 0.27+0.34-0.61 != 0 Test script: --------------- <?php echo((0.27+0.34)-0.61); ?> Expected result: ---------------- 0 Actual result: -------------- 1.1102230246252E-16 ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/bug.php?id=52415&edit=1