Bug #78492 [Com]: Comparing Value from equation to 100

Edit report at https://bugs.php.net/bug.php?id=78492&edit=1 ID: 78492 Comment by: sinus at sinpi dot net Reported by: email at brunofaria dot pt Summary: Comparing Value from equation to 100 Status: Not a bug Type: Bug Package: *Math Functions Operating System: Windows 10 PHP Version: 7.3.9 Assigned To: cmb Block user comment: N Private report: N New Comment: You should always compare floats with <, >, <= or >=. In your case, make it $value>99.999 and you'll be good. Previous Comments: ------------------------------------------------------------------------ [2019-09-04 17:58:54] phpbugreports at gmail dot com convert to strings is sonsense even if it works by luck, limited precision was already explained, the value is something like "100.0000000000000142108547152020037174224853515625" if(100 == (int)$value) if(100 === (int)$value) one of both would work <?php $value = 61.8 + 20.1 + 11.4 + 6.7; ini_set('precision', 1000); if(100 == (int)$value) { echo "true: $value\n"; } else { echo "false: $value\n"; } ?> ------------------------------------------------------------------------ [2019-09-04 17:47:12] email at brunofaria dot pt I think I'm going to convert both values to strings and them compare them to work around this problem. ------------------------------------------------------------------------ [2019-09-04 17:35:31] email at brunofaria dot pt Doesn't matter if its == or === always returns false. Also, the result from the foreach loop is exactly '100' and I'm comparing to 100 , its the same string representation. ------------------------------------------------------------------------ [2019-09-04 16:17:05] sinus at sinpi dot net Rule #1: never compare floats with ==. ------------------------------------------------------------------------ [2019-09-04 14:34:26] cmb@php.net Floating point values have a limited precision. Hence a value might not have the same string representation after any processing. That also includes writing a floating point value in your script and directly printing it without any mathematical operations. If you would like to know more about "floats" and what IEEE 754 is, read this: http://www.floating-point-gui.de/ Thank you for your interest in PHP. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=78492 -- Edit this bug report at https://bugs.php.net/bug.php?id=78492&edit=1