30-seconds-of-code/snippets/js/s/successive-values-array.md

title, type, language, tags, cover, excerpt, dateModified

title	type	language	tags	cover	excerpt	dateModified
Array of successive values	snippet	javascript	array	laptop-view	Applies a function to each element from left to right, returning an array of successively reduced values.	2020-10-22T20:24:04+03:00

Applies a function against an accumulator and each element in the array (from left to right), returning an array of successively reduced values.

• Use Array.prototype.reduce() to apply the given function to the given array, storing each new result.

const reduceSuccessive = (arr, fn, acc) =>
  arr.reduce(
    (res, val, i, arr) => (res.push(fn(res.slice(-1)[0], val, i, arr)), res),
    [acc]
  );

reduceSuccessive([1, 2, 3, 4, 5, 6], (acc, val) => acc + val, 0);
// [0, 1, 3, 6, 10, 15, 21]