30-seconds-of-code/snippets/bifurcate.md

title, tags, expertise, cover, firstSeen, lastUpdated

title	tags	expertise	cover	firstSeen	lastUpdated
Bifurcate array based on values	array	intermediate	blog_images/two-cities.jpg	2018-02-14T12:13:07+02:00	2020-11-01T20:50:57+02:00

Splits values into two groups, based on the result of the given filter array.

• Use Array.prototype.reduce() and Array.prototype.push() to add elements to groups, based on filter.
• If filter has a truthy value for any element, add it to the first group, otherwise add it to the second group.

const bifurcate = (arr, filter) =>
  arr.reduce((acc, val, i) => (acc[filter[i] ? 0 : 1].push(val), acc), [
    [],
    [],
  ]);

bifurcate(['beep', 'boop', 'foo', 'bar'], [true, true, false, true]);
// [ ['beep', 'boop', 'bar'], ['foo'] ]