24156 2009-02-25 01:47:21 -0800 Unary + conversion to number fails for negative hexadecimal (-0xff) 0x 2011-09-07 00:54:05 -0700 1 1 1 Unclassified WebKit JavaScriptCore 528+ (Nightly build) All All RESOLVED INVALID http://groups.google.com/group/comp.lang.javascript/msg/8f8fcfdc42ee3960 P2 Normal --- 1 jorgechamorro zwarich barraclough jorgechamorro zwarich oldest_to_newest 110924 0 jorgechamorro 2009-02-25 01:47:21 -0800 See: javascript:s= "0x12";alert((+s)+ ","+ parseInt(s,16)); //-> 18,18 but: javascript:s= "-0x12";alert((+s)+ ","+ parseInt(s,16)); //-> NaN,-18 111116 1 zwarich 2009-02-25 23:22:11 -0800 This works as expected. See section 9.3.1 of the ECMA spec: http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-262.pdf The ToNumber operation (which is used by the unary plus operator) only handles negative signs for decimal numbers, not hex or octal. It might be a bit strange, but it's the spec. 111142 2 jorgechamorro 2009-02-26 01:03:21 -0800 (In reply to comment #1) > > The ToNumber operation (which is used by the unary plus operator) only handles > negative signs for decimal numbers, not hex or octal. It might be a bit > strange, but it's the spec. FF, Opera and Chrome handle them fine, and that might be perceived as "better". Better than the spec -if you want- but better, after all. Now, what's the best browser ? Not Safari when it comes to hex string conversion to number... IMO, in this case better is better than the spec. Safari is doing it to/in-spec, but worse. 111183 3 zwarich 2009-02-26 07:50:25 -0800 If it's a potential compatibility issue down the road, then it probably makes sense to match Firefox on this. 463214 4 barraclough 2011-09-07 00:54:05 -0700 This was a bug in other browsers, and fixed in the latest FireFox. Behaves correctly.