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

title, tags, expertise, firstSeen, lastUpdated

title	tags	expertise	firstSeen	lastUpdated
Logical or for functions	function,logic	beginner	2020-05-13T11:35:46+03:00	2020-10-19T18:51:03+03:00

Checks if at least one function returns true for a given set of arguments.

• Use the logical or (||) operator on the result of calling the two functions with the supplied args.

const either = (f, g) => (...args) => f(...args) || g(...args);

const isEven = num => num % 2 === 0;
const isPositive = num => num > 0;
const isPositiveOrEven = either(isPositive, isEven);
isPositiveOrEven(4); // true
isPositiveOrEven(3); // true