Bug #80163 [NEW]: An error in operating a cast to an int

From: peter dot j dot burling at skymesh dot com dot au Operating system: Linux - Fedora fc30.x86_64 PHP version: 7.3.22 Package: Math related Bug Type: Bug Bug description:An error in operating a cast to an int Description: ------------ Casting to an int where a subtraction equals 0.2, when multiplied by 10 and cast to an int returns a value of 1. If the subtraction equals 0.3 then the result of the above cast will equal 3 Test script: --------------- $kwatts = ((int)(($row[7]Â - $row[4]) * 10))/10 ; with $row[7] = 55.40 with $row[4] = 55.20 but returning a $kwatts value of 0.1 php > $a = 0.1; php > $b = 0.3; php > echo $b - $a ; 0.2 php > echo ($b - $a)* 10 ; 2 php > echo(int)($b - $a)* 10 ; 0 php > echo(int)(($b - $a)* 10) ; 1 php > echo(int)(10 * ($b - $a)) ; 1 php > echo(int)((10 * ($b - $a))) ; 1 -- Edit bug report at https://bugs.php.net/bug.php?id=80163&edit=1 -- Fix committed: https://bugs.php.net/fix.php?id=80163&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=80163&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=80163&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=80163&r=needscript Try newer version: https://bugs.php.net/fix.php?id=80163&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=80163&r=support Expected behavior: https://bugs.php.net/fix.php?id=80163&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=80163&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=80163&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=80163&r=globals PHP version support discontinued: https://bugs.php.net/fix.php?id=80163&r=phptooold Daylight Savings: https://bugs.php.net/fix.php?id=80163&r=dst IIS Stability: https://bugs.php.net/fix.php?id=80163&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=80163&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=80163&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=80163&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=80163&r=mysqlcfg