Edit report at https://bugs.php.net/bug.php?id=64307&edit=1
ID: 64307 Updated by: paj...@php.net Reported by: sokkis at gmail dot com Summary: Floating point error -Status: Open +Status: Not a bug Type: Bug Package: Variables related Operating System: Gentoo linux 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. Previous Comments: ------------------------------------------------------------------------ [2013-02-27 09:31:27] sokkis at gmail dot com Description: ------------ Floating point rounded when print, but won't on subtraction. Test script: --------------- <?php $n1 = 905000; $n2 = 0.27; $ertek =$n1*$n2; $egesz = round( $ertek ); $eredmeny = $ertek-$egesz; echo "$ertek - $egesz = $eredmeny\n"; $n1 = 905000; $n2 = 0.27; $ertek =$n1*$n2; $egesz = (int) $ertek; $eredmeny = $ertek-$egesz; echo "$ertek - $egesz = $eredmeny"; Expected result: ---------------- 244350 - 244350 = 0 244350 - 244350 = 0 Actual result: -------------- 244350 - 244350 = 2.9103830456734E-11 244350 - 244350 = 2.9103830456734E-11 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=64307&edit=1
