Edit report at https://bugs.php.net/bug.php?id=64307&edit=1
ID: 64307 Updated by: ni...@php.net Reported by: sokkis at gmail dot com Summary: Floating point error 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: @sokkis: I don't quite understand what you are asking, but maybe you are looking for the "precision" ini option, which controls with how much precision floats will be displayed when converted to string. See here for an example: http://codepad.viper-7.com/o4M9q3 Previous Comments: ------------------------------------------------------------------------ [2013-02-27 09:46:45] sokkis at gmail dot com "Floating point values have a limited precision" It's ok, but why not: 244350,00000000... - 244350 = 2.9103830456734E-11 the output? So, if floating point variable has limited precision, it has it if echod, and has if make subractions, or any other. ------------------------------------------------------------------------ [2013-02-27 09:42:45] paj...@php.net 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. ------------------------------------------------------------------------ [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
