Javascript Memoized Functions

Memoization is an optimization technique that makes applications more efficient and hence faster. It does this by storing computation results in cache, and retrieving that same information from the cache the next time it's needed instead of computing it again.

function memoize(fn) {
  const cache = new Map();
  return (...args) => {
    const key = JSON.stringify(args);
    if (cache.has(key)) {
      console.log(`fetching from cahce for args ${key}`);
      return cache.get(key);
    }
    const data = fn.apply(this, args);
    cache.set(key, data);
    return data;
  };
}

const addThreeNums = (a, b, c) => a + b + c;
const add = memoize(addThreeNums);
console.log(add(1, 2, 3));
console.log(add(1, 2, 3));

const factorial = memoize((x) => {
  if (x === 0) return 1;
  else return x * factorial(x - 1);
});

console.log(factorial(5));
console.log(factorial(6));