Bug #53865 [Com]: (float)0 * -1 = minus zero (-0)

From: Date: Fri, 28 Jan 2011 10:33:54 +0000
Subject: Bug #53865 [Com]: (float)0 * -1 = minus zero (-0)
References: 1  Groups: php.bugs 
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Edit report at http://bugs.php.net/bug.php?id=53865&edit=1 ID: 53865 Comment by: dmitrij at stepanov dot lv Reported by: dmitrij at stepanov dot lv Summary: (float)0 * -1 = minus zero (-0) Status: Bogus Type: Bug Package: Scripting Engine problem Operating System: Windows 7 PHP Version: 5.3.5 Block user comment: N Private report: N New Comment: I guess the link should be http://en.wikipedia.org/wiki/IEEE_754 Previous Comments: ------------------------------------------------------------------------ [2011-01-28 11:23:02] derick@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://docs.sun.com/source/806-3568/ncg_goldberg.html Thank you for your interest in PHP. . ------------------------------------------------------------------------ [2011-01-28 10:03:40] dmitrij at stepanov dot lv Description: ------------ See test script. Test script: --------------- var_dump( (float)0 * -1); Expected result: ---------------- float(0) Actual result: -------------- float(-0) ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/bug.php?id=53865&edit=1

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