#35898 [NEW]: round() documentation incorrect

From: matt at equaliser dot net Operating system: Linux PHP version: Irrelevant PHP Bug Type: Documentation problem Bug description: round() documentation incorrect Description: ------------ Documentation reads round -- Rounds a float Description float round ( float val [, int precision] ) Returns the rounded value of val to specified precision (number of digits after the decimal point). precision can also be negative or zero (default). Should read: Returns the rounded value of val's floating point representation in memory to specified precision (number of digits after the decimal point). WARNING: This function may not return expected results for floating point numbers in memory whose string representation ends in a 5. eg: round (7.875 , 1); returns '7.88' $a = 45; $b = $a * .175; round ($b , 1); May return either '7.88' or '7.87'. See http://www.php.net/manual/en/language.types.float.php If you would like to know more about "floats" and what IEEE 754 is read this: http://docs.sun.com/source/806-3568/ncg_goldberg.html $ -- Edit bug report at http://bugs.php.net/?id=35898&edit=1 -- Try a CVS snapshot (PHP 4.4): http://bugs.php.net/fix.php?id=35898&r=trysnapshot44 Try a CVS snapshot (PHP 5.1): http://bugs.php.net/fix.php?id=35898&r=trysnapshot51 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=35898&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=35898&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=35898&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=35898&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=35898&r=needscript Try newer version: http://bugs.php.net/fix.php?id=35898&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=35898&r=support Expected behavior: http://bugs.php.net/fix.php?id=35898&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=35898&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=35898&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=35898&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=35898&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=35898&r=dst IIS Stability: http://bugs.php.net/fix.php?id=35898&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=35898&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=35898&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=35898&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=35898&r=mysqlcfg