JavaScript · More array and object methods

Object.groupBy()

Groups items into an object keyed by the callback result.

javascriptRunnable example javascript course

Syntax

Object.groupBy(items, fn)

Example

Try it

console.log(Object.groupBy([1, 2, 3, 4], n => n % 2 ? "odd" : "even"));

Reference pages are the quick answer. The course explains the why, shows the full example and ends with a challenge.