ID: 37202 Updated by: [EMAIL PROTECTED] Reported By: ruben_ruben at yahoo dot com -Status: Open +Status: Bogus Bug Type: Variables related Operating System: win xp pro sp2 PHP Version: 5.1.2 New Comment:
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://docs.sun.com/source/806-3568/ncg_goldberg.html Thank you for your interest in PHP. Previous Comments: ------------------------------------------------------------------------ [2006-04-25 20:42:21] ruben_ruben at yahoo dot com Description: ------------ In loops like While and For with increases with point decimal fails the precision. Reproduce code: --------------- $i=71; $i2 = 82; $increases = .1; for($i; $i <= $i2; $i = $i + $increases) { echo "$i<br>"; } //**** or ****** $i=1.5; $i2 = 2; $increases = .001; while($i <= $i2) { echo "$i<br>"; $i = $i + $increases; } Expected result: ---------------- with $i=71; $i2 = 82; $increases = .1; it must be: 71 71.1 . . . 81.9 82 *************** with $i=1.5; $i2 = 2; $increases = .001; it must be: 1.5 1.501 1.502 . . . 1.999 2 Actual result: -------------- both with $i=71; $i2 = 82; generates: 71 71.1 . . 79.8 79.899999999999 79.999999999999 . . 81.899999999999 81.999999999999 *************** both with $i=1.5; $i2 = 2; $increases = .001; generates: 1.5 1.501 1.502 . . 1.954 1.9549999999999 1.9559999999999 . . 1.9989999999999 1.9999999999999 ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=37202&edit=1
