Return sum of even numbers in fibonacci series which are even.

memoizedFibonacci.js

let cache = [];
function fib(num) {
  if (cache[num] == undefined) {
    if (num == 0) {
      cache[0] = 0;
    } else if (num == 1) {
      cache[1] = 1;
    } else {
      cache[num] = fib(num - 1) + fib(num - 2);
    }
  }
  return cache[num];
}

function cached(func) {
  let cache = new Map();
  return function (num) {
    if (cache.has(num)) {
      return cache.get(num);
    } else {
      let res = func(num);
      cache.set(num, res);
      return res;
    }
  };
}

let cachedFib = cached(fib);

function getEvenFib(num) {
  let results = [];
  for (let i = 0; i <= num; i++) {
    let res = cachedFib(i);
    if (res % 2 == 0) {
      results.push(res);
    }
  }
  return results.reduce((a, b) => a + b, 0);
}

console.log(getEvenFib(12));