typeof null

Brendan Eich brendan at mozilla.com
Thu May 10 15:02:05 PDT 2012


Allen Wirfs-Brock wrote:
> Note that in this and many other similar situations the isFoo method is actually redundant.  You would get the same effect by saying: 
>
>
>   if (obj1.doFooishThings) obj1.doFooishThings();
>
> this suggests that a useful operator might be a conditional property access, perhaps something like: 
>
>
> ??obj.doFooishThings();
>
> which parses as
> CallExpression :
>      ?? MemberExpression Arguments
>
> If conditionally calls the value of the MemberExpression if it is not undefined. 
>

CoffeeScript has foo?.bar ... and foo.baz?(...) in lieu of

   if (foo != null) foo.bar ...

and

   if (foo.baz != null) foo.baz(...)

where all ... are meta. We've talked about these a bit in TC39 but I 
don't recall any definite outcome.

/be


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