Edit report at https://bugs.php.net/bug.php?id=54547&edit=1
ID: 54547 Comment by: foobla at spambog dot com Reported by: peter dot ritt at gmx dot net Summary: wrong equality of string numbers Status: Verified Type: Bug Package: Unknown/Other Function Operating System: linux PHP Version: 5.3.6 Assigned To: dmitry Block user comment: N Private report: N New Comment: I don't think it's about PHP_MAX_INT, rather about the maximum precision of a double/float. "==" converts both strings to numbers (after spending CPU cycles to detect whether they look like numbers), as described in http://www.phpsadness.com/sad/47 once converted, the floats seem to actually *be* equal, even with "===": php -r ' $a = (double)"9223372036854775807"; $b = (double)"9223372036854775808"; var_dump($a, $b, $a == $b, $a === $b); ' float(9.2233720368548E+18) float(9.2233720368548E+18) bool(true) bool(true) Previous Comments: ------------------------------------------------------------------------ [2011-04-18 03:04:14] cataphr...@php.net Maybe this should be Won't Fix to keep it consistent with 9223372036854775807 == 9223372036854775808 (with number literals). ------------------------------------------------------------------------ [2011-04-17 05:44:03] cataphr...@php.net The following patch has been added/updated: Patch Name: bug54547-2.diff Revision: 1303011843 URL: http://bugs.php.net/patch-display.php?bug=54547&patch=bug54547-2.diff&revision=1303011843 ------------------------------------------------------------------------ [2011-04-17 01:59:59] cataphr...@php.net The following patch has been added/updated: Patch Name: bug54547.diff Revision: 1302998399 URL: http://bugs.php.net/patch-display.php?bug=54547&patch=bug54547.diff&revision=1302998399 ------------------------------------------------------------------------ [2011-04-16 20:07:43] peter dot ritt at gmx dot net Description: ------------ comparison of strings using == shows wrong results when both strings are numbers (digits) around PHP_MAX_INT; the same comparison using === works correctly; tested on 64 bit systems only, affects also PHP 5.3.5 Test script: --------------- $a = '9223372036854775807'; $b = '9223372036854775808'; if ($a == $b) { echo "$a == $b\n"; } else { echo "$a != $b\n"; } // displays 9223372036854775807 == 9223372036854775808 Expected result: ---------------- should display 9223372036854775807 != 9223372036854775808 Actual result: -------------- displays 9223372036854775807 == 9223372036854775808 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=54547&edit=1
