note 117341 added to function.ceil

Note that 'ceil' can show unexpected behaviour when using float values due to inaccuracies in the float system and PHP tendency to freely limiting the number of digits it displays to the user. It might like it is rounding up values that end in 0 (zero) but actually PHP is not showing that the value is not exactly the value it shows. <?PHP echo('Displaying 13915.0000000000018190 : '. 13915.0000000000018190); echo('<br>'); echo('Result ceil(13915.0000000000018190) :'.ceil(13915.0000000000018190)); echo('<br>'); ?> For example 13915 cannot be represented as exactly 13915 but becomes 13916.0000000000018190 and 'ceil' will therefore round it up to 13916. <?PHP $value = 12650 * 1.1; echo('Expected behaviour : ceil(12650 * 1.1) = ceil(13915) = 13915'); echo('<br>'); echo('Using only ceil :'.ceil($value)); echo('<br>'); echo('Showing decimals : '.number_format($value - floor($value), 16)); echo('<br>'); echo('Using ceil + round : '.ceil(round($value,4))); ?> So if 'ceil' looks like it is not working correctly and rounding up figures that end in 0 (zero) then this might be the cause of this behaviour. Adding a simple 'round' before the applying the 'ceil' solves this problem. ---- Server IP: 72.52.91.14 Probable Submitter: 124.39.122.119 ---- Manual Page -- http://php.net/manual/en/function.ceil.php Edit -- https://master.php.net/note/edit/117341 Del: integrated -- https://master.php.net/note/delete/117341/integrated Del: useless -- https://master.php.net/note/delete/117341/useless Del: bad code -- https://master.php.net/note/delete/117341/bad+code Del: spam -- https://master.php.net/note/delete/117341/spam Del: non-english -- https://master.php.net/note/delete/117341/non-english Del: in docs -- https://master.php.net/note/delete/117341/in+docs Del: other reasons-- https://master.php.net/note/delete/117341 Reject -- https://master.php.net/note/reject/117341 Search -- https://master.php.net/manage/user-notes.php