This is used to determine if something is a primitive or not.
`typeof null` returns 'object' even though it is not an object and `typeof
function() {}` returns 'function' even though it is an object. Basically
'typeof' alone is not enough to determine if something is primitive or
object. `instanceof Object` has some edge cases for instance if an object
is created with `Object.create(null)` or is from another global context.
On Friday, September 19, 2014 1:00:19 AM UTC-7, enormouspenguin wrote:
>
> if (obj === Object(obj)) return 'object';
>
> That is cut from chaijs/type-detect/blob/master/lib/type.js#L42
> <https://github.com/chaijs/type-detect/blob/master/lib/type.js#L42>.
>
> My first guess (probably a joke):
>
> obj === Object(obj)
>
> is somewhat similar to
>
> obj instanceof Object
>
> My second guess is that it's used to distinguish between primitive value
> (created using literal) and primitive object (created using instantiation)
> such as 1 and (new Number(1)).
>
> But typeof operator could correctly distinguish by itself:
>
> typeof 1 === 'number'
> typeof new Number(1) === 'object'
>
> Also I feel line 41
> <https://github.com/chaijs/type-detect/blob/master/lib/type.js#L41> is
> unnecessary too:
>
> if (obj === undefined) return 'undefined';
>
> I don't know why would those 2 lines of code be there while
>
> return typeof obj;
>
> in line 43
> <https://github.com/chaijs/type-detect/blob/master/lib/type.js#L43> could
> as well be enough to substitute both.
>
> Is there any edge case here?
>
> May be I am missing something internal here?
>
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