Accessing (n)th key from an object

[Augusto Moura]

Assuming `Object.keys` has the same order as a simple `for..in` (as stated
in mdn)[
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys],
we can already implement a function to build a iterator from object keys,
and then we can destruct or use others helpers to minimize the array
creation. Something like:

``` js
function* keysIterator(obj) {
  for (const key in obj) {
    if (obj.hasOwnProperty(key)) {
      yield key;
    }
  }
}
const obj = { foo: 12, bar: 89 };

// Using destructuring
const [firstProp, secondProp, ...othersKeys] = keysIterator(obj);

// Using some helper functions
const props = take(2, 10)(obj);
```

The discussion IMHO is if we need that as a built in helper (maybe
`Object.keysIterator()`), and if we need to extend it to `Object.values`
and `Object.entries`.

Em ter, 24 de abr de 2018 às 10:54, somonek <somonek at gmail.com> escreveu:

> Hi all,
>
> Assuming that
>
> const myObject = {
>   one: 123,
>   two: 456,
> };
>
> could
> myObject[in 0] === 'one' // true
>
> be a better alternative of
> Object.keys(myObject)[0]
>
> and
> myObject[in 3] === undefined
>
> without the need to convert all the object keys into an array, but
> directly accessing one.
>
> Best,
> Serghei
>
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>
-- 
Augusto Moura
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