||= is much needed?

Herby Vojčík herby at mailbox.sk
Thu Jun 14 11:23:00 PDT 2012

Tab Atkins Jr. wrote:
> On Thu, Jun 14, 2012 at 11:01 AM, Brendan Eich<brendan at mozilla.com>  wrote:
>> We have a problem with || indeed. The question is whether the solution
>> should equate null and undefined. CoffeeScript chose the
>> conceal-the-difference path and it has users. The users who want null to be
>> distinct from undefined are neither CoffeeScript users, nor || users (in
>> their defaulting code). They must be doing === undefined test. That is rare
>> too (not quite as rare as passing null instead of undefined as intentional
>> default trigger in my experience).
>> What is your reason for preferring === undefined over == null, since we have
>> a dilemma and users often use an even looser (falsy, viz ||) test than ==
>> null, but some use == null and others use === undefined, for the defaulting
>> trigger?
> I don't claim to be typical in cases like this, but my experience is
> similar to Herby's - I use || most of the time just because it's short
> and easy, but switch to "x === undefined" with a trinary if x might be
> falsey.
Yeah, I switch, too. If I see it is needed, and don't forget it. That is 
why || is uneasy, ?? would remove the fear (in Kent-and-Ward TDD sense).
> ~TJ

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