PHP 4.0 Bug #5819: Floating-point precison lost only but always for some "magic" numbers

From: nightfall@mail.ru Operating system: Win32 (PHP 4.0.1), Linux (PHP 4.0), most likely any other PHP version: 4.0.1 PHP Bug Type: Other Bug description: Floating-point precison lost only but always for some "magic" numbers Look at the following sample: $a=1.16; $b=intval($a*100)/100; It's already classic, but... the result is NOT 1.16 again! Actually $b=1.15 What??! Try multiplying by 1000, and you will get the right one, 1.16 It's funny, how do you think? This will work with any "magic" number such as 0.29, 0.58, 1.16, 2.32 e t.c., i.e 0.29*(2^n). I haven't checked all other possible numbers (joke ;-), but it seems to work the same way ANYWHERE. (At least i can guarantee in PHP 4.0 and 4.0.1 for Win32 and Linux, no matter). I think, it's related to PHP's internal floating-point engine, but... but... you will see at your own. -- Helen (nightfall@mail.ru)