fakeMap in Array@reduce

fakeMap.js

var arr = [1, 2, 3, 4];


function handleNext(value) {
  return value * 2
}


Array.prototype.fakeMap = function(cb) {
  return this.reduce((accumulator, next, index) => {
    accumulator.push(cb(next))
    
    return accumulator;
  }, []);
}


var mappedArr = arr.map(handleNext);
var reducedArr = arr.fakeMap(handleNext);


console.log(reducedArr);
console.log(mappedArr);