From: rasmus at mindplay dot dk Operating system: Any PHP version: 5.2.6 PHP Bug Type: Scripting Engine problem Bug description: non-native conversions from float to string
Description: ------------ When using strval(), implicit conversion or type-casting, floats are converted using locale-aware display formatting, rather than native formatting, as understood by most other software (and PHP itself). Please understand that this is a complex problem, which requires a lengthy analysis and many examples. I have spent almost 6 hours analyzing this problem in-depth, and created a complete report explaining the problem, suggesting changes, and recommending ways to implement these changes. Please, don't discard this report without careful consideration - there are fundamental problems with float-handling in PHP, which should be taken seriously. For the full description and examples, please see this page: http://public.test.fynskemedier.dk/float/ Thank You. Reproduce code: --------------- <?php setlocale(LC_NUMERIC, 'danish'); function ftos($f) { return is_float($f) ? sprintf('%.14F', $f) : 'NaN'; } $a = 1234.01234567890123456789; echo "accurate value: " . ftos($a) . "\n\n"; echo "casting float to string: "; $s = (string) $a; var_dump($s); echo "casting back to float: "; echo ftos( (float) $s ) . "\n\n"; ?> The above is a very simple example, demonstrating one of the issues most commonly encountered by beginning PHP developers. Please find many more examples and in-depth explanations below: http://public.test.fynskemedier.dk/float/ Expected result: ---------------- accurate value: 1234.01234567890128 casting float to string: string(19) "1234.01234567890128" casting back to float: 1234.01234567890128 Actual result: -------------- accurate value: 1234.01234567890128 casting float to string: string(13) "1234,01234568" casting back to float: 1234.00000000000000 -- Edit bug report at http://bugs.php.net/?id=45365&edit=1 -- Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=45365&r=trysnapshot52 Try a CVS snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=45365&r=trysnapshot53 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=45365&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=45365&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=45365&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=45365&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=45365&r=needscript Try newer version: http://bugs.php.net/fix.php?id=45365&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=45365&r=support Expected behavior: http://bugs.php.net/fix.php?id=45365&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=45365&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=45365&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=45365&r=globals PHP 4 support discontinued: http://bugs.php.net/fix.php?id=45365&r=php4 Daylight Savings: http://bugs.php.net/fix.php?id=45365&r=dst IIS Stability: http://bugs.php.net/fix.php?id=45365&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=45365&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=45365&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=45365&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=45365&r=mysqlcfg
