Bug #75690 [NEW]: PHP 7.1 changes precision when using json_encode() to encode floats

From: renan dot nannetti at gmail dot com Operating system: RHEL6 PHP version: 7.1.12 Package: JSON related Bug Type: Bug Bug description:PHP 7.1 changes precision when using json_encode() to encode floats Description: ------------ Description: ------------ json_encode() is presenting rounding issues when trying to encode float values. Note: I'm using serialize_precision equals to -1 in my php.ini. Test script: --------------- <?php echo json_encode((floatval(-0.717655) - floatval(6.7173))); Expected result: ---------------- '-7.434955' Actual result: -------------- '-7.4349549999999995' -- Edit bug report at https://bugs.php.net/bug.php?id=75690&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=75690&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=75690&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=75690&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=75690&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=75690&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=75690&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=75690&r=needscript Try newer version: https://bugs.php.net/fix.php?id=75690&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=75690&r=support Expected behavior: https://bugs.php.net/fix.php?id=75690&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=75690&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=75690&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=75690&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=75690&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=75690&r=dst IIS Stability: https://bugs.php.net/fix.php?id=75690&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=75690&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=75690&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=75690&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=75690&r=mysqlcfg