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From: "Christoph M. Becker" <cmbecker69@arcor.de>
Newsgroups: comp.lang.javascript
Subject: IE and IEEE 754 (was: IE and IEE 754)
Date: Wed, 27 Aug 2014 22:08:48 +0200
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RobG wrote:

> In most browsers:
> 
>   0.57 + 8.36 + 3.36 + 0.19 = 12.479999999999999
> 
> in IE it returns:
> 
>   12.479999999999998
> 
> Is IE wrong, or is the above difference allowable within IEEE 754?

Both string representations will be parsed as the same double-precision
64-bit binary format IEEE 754 value[1]:

  100000000101000111101011100001010001111010111000010100011110101

(Therefore: 12.479999999999999 === 12.479999999999998)

The different string representation is allowed for conforming ECMAScript
implementations according to ECMA-262 5.1 Edition, section 9.8.1 step 5[2].

[1] <http://www.merlyn.demon.co.uk/js-exact.htm#DW4>
[2] <http://ecma-international.org/ecma-262/5.1/#sec-9.8.1>

-- 
Christoph M. Becker