JSFiddle - React, Tailwind, and code Playground

by serGlazkov

HTML

<div>myMap function</div>

JavaScript

function map(fn, arr) {
  const [first, ...other] = arr;
  if (first === undefined) {
    return [];
  }
  
  return [fn(first), ...map(fn, other)];
}

const multiple = (item) => item * 2

const result = map(multiple, [1, 2, 3])
console.log('result', result);