Subj : Re: Date() == new Date()
To   : Celso Aguiar
From : Brendan Eich
Date : Wed Sep 08 2004 03:25 pm

Celso Aguiar wrote:
> Ecma wise, what's the expected return from the above, true or false?
> I know 'Date()' called as a function returns a string, while 'new Date()'
> returns an object. I also know Date.toString() is getting called (SM)
> for 'new Date()' before the '==' equality operator is evaluated (to 'true').
> What's the expected return for Date() === new Date()?
> Thanks for the attention!


There is no well-defined result for eval("Date() == new Date()"), for 
one reason because there is a race condition: the new Date() could 
happen in a later second than the Date(), resulting in different strings.

The result is undefined for another reason: ECMA-262 Edition 3 specifies 
that Date() return "a string representing the current time (UTC)" 
(15.9.2).  ECMA-262 Ed. 3 also says that a Date object converts to a 
string whose contents are "implementation-dependent, but are intended to 
represent the Date in the current time zone in a convenient, 
human-readable form" (15.9.5.2).

So even if there were no race condition, ECMA does not require to result 
of Date() to match the result of Date.prototype.toString().

/be

.