On Jul 26, 2014, at 20:36 , Kevin Smith <zenpars...@gmail.com> wrote:
> * As far as I can tell, `hasOwnProperty` is mainly used to implement maps via > objects. `Map` will eliminate this use case. > > To a certain extent yes, but not completely. Objects-as-maps will still be > used quite frequently as object literals passed into functions (as an options > object, for example). > > I think that there is still a need here. Yes, but it’s much less urgent. > Since we are really interested in *keys*, what about this: > > Object.hasKey(obj, someKey); Ah, good point! I hadn’t thought of symbols as property keys. > which would be a more ergonomic and efficient way of saying: > > Object.keys(obj).some(key => key === someKey) Did you mean `Reflect.ownKeys()`? How about: ```js Reflect.ownKeys(obj).indexOf(someKey) >= 0 ``` Or, maybe in ES7: ```js Reflect.ownKeys(obj).contains(someKey) ``` -- Dr. Axel Rauschmayer a...@rauschma.de rauschma.de
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