Thoughts on IEEE P754

Jason Orendorff jason.orendorff at
Fri Aug 22 07:22:36 PDT 2008

On Fri, Aug 22, 2008 at 6:22 AM, Sam Ruby <rubys at> wrote:
> On Fri, Aug 22, 2008 at 2:30 AM, Jason Orendorff
> <jason.orendorff at> wrote:
>>  var a = [];
>>  a[0] = "first";
>>  a[0.0m] = "second";   // a second property?
>>  a[0.000m] = "third";   // a third?
> [...]
> It seems to me that if trailing zeros are retained in a call to
> ToString, then to be consistent with ES3, the three assignments above
> would produce three properties.  And if trailing zeros are lost, you
> would expect to only have one.  Both approaches are internally
> consistent, and it surprises me to see either one characterized as
> "breaking" array lookup.

Well, the intuition is that two equal numbers should index the same
property.  This is an invariant in ES3 and it makes a lot of sense.


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