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

title, tags, expertise, cover, firstSeen, lastUpdated

title	tags	expertise	cover	firstSeen	lastUpdated
Drop list elements from the right based on function	array	intermediate	blog_images/bridge-drop.jpg	2018-01-26T12:23:18+02:00	2020-10-19T18:51:03+03:00

Removes elements from the end of an array until the passed function returns true. Returns the remaining elements in the array.

• Loop through the array, using Array.prototype.slice() to drop the last element of the array until the value returned from func is true.
• Return the remaining elements.

const dropRightWhile = (arr, func) => {
  let rightIndex = arr.length;
  while (rightIndex-- && !func(arr[rightIndex]));
  return arr.slice(0, rightIndex + 1);
};

dropRightWhile([1, 2, 3, 4], n => n < 3); // [1, 2]