Examples of Array.prototype.reduce()

reducer.js

const numbers = [1, 2, 3, 4, 12, 50];
const reducer = (accumulator, currentValue) => accumulator + currentValue;
const reducedNumbers = numbers.reduce((accumulator, currentValue) => accumulator + currentValue);
const multipliedNumbers = numbers.map(x => x * 2);

console.log(numbers.reduce(reducer)); // => 72
console.log(reducedNumbers); // => 72
console.log(multipliedNumbers); // => [ 2, 4, 6, 8, 24, 100 ]