Bug #51480 [NEW]: Error on calculation 100.2 - 100.1 - 0.1

From: Operating system: Linux PHP version: Irrelevant Package: Math related Bug Type: Bug Bug description:Error on calculation 100.2 - 100.1 - 0.1 Description: ------------ Error on a simple calculation. The correct result must be zero. Google and JavaScript are wrong too. But OpenOffice Calc and GCalcTool (gnome calculator) are correct. Test script: --------------- //Try a simple calculation: $result = 100.2 - 100.1 - 0.1; echo $result; //The result is 8.520961714E-15 //And trying (inverting): $result = 100.2 - 0.1 - 100.1; echo $result; //The result is 1.42108547152E-14 Expected result: ---------------- The correct result must be zero! Actual result: -------------- 8.520961714E-15 and 1.42108547152E-14 respectively. -- Edit bug report at http://bugs.php.net/bug.php?id=51480&edit=1 -- Try a snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=51480&r=trysnapshot52 Try a snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=51480&r=trysnapshot53 Try a snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=51480&r=trysnapshot60 Fixed in SVN: http://bugs.php.net/fix.php?id=51480&r=fixed Fixed in SVN and need be documented: http://bugs.php.net/fix.php?id=51480&r=needdocs Fixed in release: http://bugs.php.net/fix.php?id=51480&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=51480&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=51480&r=needscript Try newer version: http://bugs.php.net/fix.php?id=51480&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=51480&r=support Expected behavior: http://bugs.php.net/fix.php?id=51480&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=51480&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=51480&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=51480&r=globals PHP 4 support discontinued: http://bugs.php.net/fix.php?id=51480&r=php4 Daylight Savings: http://bugs.php.net/fix.php?id=51480&r=dst IIS Stability: http://bugs.php.net/fix.php?id=51480&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=51480&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=51480&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=51480&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=51480&r=mysqlcfg