Destructuring objects from an array using map?

Question

I have wrote this simple code that destructures an array of objects to build new arrays from each key. I am learning ES6 and would like to refactor it into one line of code using destructuring but I dont fully understand how too.

let candles = [{
  open: 1,
  high: 2,
  low: 0.5,
  close: 1.5,
  volume: 200
}];
let open = candles.map(x => x.open);
let high = candles.map(x => x.high);
let low = candles.map(x => x.low);
let close = candles.map(x => x.close);
let volume = candles.map(x => x.volume);

console.log(open, high, low, close, volume);

I am thinking it should look something along the lines of this?

let [open, high, low, close, volume] = candles.map(key => key.value); 

But it is clearly wrong! Thank you for help if someone can direct me the correct way on doing this!

Answer 1

Here's a solution using Array.prototype.reduce():

const candles = [{open: 1, close: 2, low: 3, high: 4, volume: 5}, {open: 6, close: 7, low: 8, high: 9, volume: 10}];

const result = candles.reduce((a, v) => {
  Object.keys(v).forEach(k => (a[k] = a[k] || []).push(v[k]));
  return a;
}, {});

console.log(result);