Bug #54730 [Opn->Bgs]: comparison float

Edit report at http://bugs.php.net/bug.php?id=54730&edit=1 ID: 54730 Updated by: rasmus@php.net Reported by: dancho at hahpss dot com Summary: comparison float -Status: Open +Status: Bogus Type: Bug Package: Math related Operating System: Linux PHP Version: 5.3.6 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. Try adding ini_set('precision',32); to the top of your test script and it should be clear why these are not equal. Previous Comments: ------------------------------------------------------------------------ [2011-05-13 20:01:09] dancho at hahpss dot com Description: ------------ view result Test script: --------------- <?php $v=2.06667; echo var_dump($v*100000)."\n"; echo var_dump(round($v*100000,0)); echo "\nIs equal ? "; echo ($v*100000==round($v*100000,0)) ? "true" : "false"; ?> Expected result: ---------------- float(206667) float(206667) Is equal ? true Actual result: -------------- float(206667) float(206667) Is equal ? false ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/bug.php?id=54730&edit=1