How to convert Set to Array?

Question

Set seems like a nice way to create Arrays with guaranteed unique elements, but it does not expose any good way to get properties, except for generator [Set].values, which is called in an awkward way of mySet.values.next().

This would have been ok, if you could call map and similar functions on Sets. But you cannot do that, as well.

I've tried Array.from, but seems to be converting only array-like (NodeList and TypedArrays ?) objects to Array. Another try: Object.keys does not work for Sets, and Set.prototype does not have similar static method.

So, the question: Is there any convenient inbuilt method for creating an Array with values of a given Set ? (Order of element does not really matter).

if no such option exists, then maybe there is a nice idiomatic one-liner for doing that ? like, using for...of, or similar ?

Answer 1

if no such option exists, then maybe there is a nice idiomatic one-liner for doing that ? like, using for...of, or similar ?

Indeed, there are several ways to convert a Set to an Array:

using Array.from

let array = Array.from(mySet); 

Simply spreading the Set out in an array

let array = [...mySet]; 

The old-fashioned way, iterating and pushing to a new array (Sets do have forEach)

let array = []; mySet.forEach(v => array.push(v)); 

Previously, using the non-standard, and now deprecated array comprehension syntax:

let array = [v for (v of mySet)]; 

Answer 2

via https://speakerdeck.com/anguscroll/es6-uncensored by Angus Croll

It turns out, we can use spread operator:

var myArr = [...mySet]; 

Or, alternatively, use Array.from:

var myArr = Array.from(mySet);