Edit report at https://bugs.php.net/bug.php?id=65676&edit=1
ID: 65676 Updated by: ni...@php.net Reported by: pcmadnessltd at yahoo dot co dot uk Summary: position inaccurate a.xyz -Status: Open +Status: Not a bug Type: Bug Package: Unknown/Other Function Operating System: ubuntu 10.04 pae PHP Version: 5.4.19 Block user comment: N Private report: N 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://www.floating-point-gui.de/ Thank you for your interest in PHP. Previous Comments: ------------------------------------------------------------------------ [2013-09-15 16:31:51] pcmadnessltd at yahoo dot co dot uk Description: ------------ position inaccurate when adding 0.001 to a value possible solution round($num, 3); Test script: --------------- echo '<table>'; $ii =0; for($i =1; $i<= 10000; $i++) { echo '<tr>'; echo '<td>'; echo $ii; echo '</td>'; echo '</tr>'; $ii = $ii +0.001; } echo '</table>'; Expected result: ---------------- 1.459 1.46 1.461 1.462 1.463 1.464 1.465 1.466 ... 2.369 2.370 2.371 2.372 2.373 2.374 2.375 ... 3.278 3.279 3.280 3.281 Actual result: -------------- 1.459 1.46 1.4609999999999 1.4619999999999 1.4629999999999 1.4639999999999 1.4649999999999 1.4659999999999 ... 2.3689999999999 2.3699999999999 2.3709999999998 2.3719999999998 2.3729999999998 2.3739999999998 2.3749999999998 ... 3.2769999999998 3.2779999999998 3.2789999999997 3.2799999999997 and so on ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=65676&edit=1
