robertoandres24 · February 8, 2019 18:33
diff --git a/index.js b/index.js
 var groupBy = function(xs, key) {
  return xs.reduce(function(rv, x) {
    (rv[x[key]] = rv[x[key]] || []).push(x);
    return rv;
  }, {});
 };

 console.log(groupBy(['one', 'two', 'three'], 'length'));
	var groupBy = function(xs, key) {
	return xs.reduce(function(rv, x) {
	(rv[x[key]] = rv[x[key]] \|\| []).push(x);
	return rv;
	}, {});
	};

	console.log(groupBy(['one', 'two', 'three'], 'length'));