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

title, tags, firstSeen, lastUpdated

title	tags	firstSeen	lastUpdated
compose	function,intermediate	2017-12-17T16:41:31+02:00	2020-10-22T20:23:47+03:00

Performs right-to-left function composition.

• Use Array.prototype.reduce() to perform right-to-left function composition.
• The last (rightmost) function can accept one or more arguments; the remaining functions must be unary.

const compose = (...fns) =>
  fns.reduce((f, g) => (...args) => f(g(...args)));

const add5 = x => x + 5;
const multiply = (x, y) => x * y;
const multiplyAndAdd5 = compose(
  add5,
  multiply
);
multiplyAndAdd5(5, 2); // 15