Doc #77778 [NEW]: -0.0 and 0.0 are distinct values.

From: lewisje at alumni dot iu dot edu Operating system: CentOS 6 PHP version: Irrelevant Package: Documentation problem Bug Type: Documentation Problem Bug description:-0.0 and 0.0 are distinct values. Description: ------------ --- From manual page: https://php.net/language.types.boolean --- Among the values listed as falsy is "the float 0.0 (zero)", but the float -0.0 is not listed; however, it is both falsy and distinct from 0.0: As ought to be pointed out in https://php.net/language.types.float, IEEE-754 floating-point arithmetic includes distinct 0.0 and -0.0 values; even though they will be treated as equal under strict equality, 1/0.0 is INF, while 1/-0.0 is -INF, again as in the IEEE-754 specification. Test script: --------------- <?php var_dump(1/0.0); // float(INF) var_dump(1/-0.0); // float(-INF) var_dump(-0.0 === 0.0); // bool(true) var_dump((bool)-0.0); // bool(false) ?> Expected result: ---------------- Based on the literal documentation, (bool)-0.0 ought to be true. Actual result: -------------- (bool)-0.0 is false, and as the other statements show, -0.0 can be distinguished from 0.0, which means that it is another falsy value. -- Edit bug report at https://bugs.php.net/bug.php?id=77778&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=77778&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=77778&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=77778&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=77778&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=77778&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=77778&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=77778&r=needscript Try newer version: https://bugs.php.net/fix.php?id=77778&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=77778&r=support Expected behavior: https://bugs.php.net/fix.php?id=77778&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=77778&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=77778&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=77778&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=77778&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=77778&r=dst IIS Stability: https://bugs.php.net/fix.php?id=77778&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=77778&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=77778&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=77778&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=77778&r=mysqlcfg