Memoization in JavaScript using ES6 structures

js-memoization.js

function memoize(fn) {
  let state = {};
  
  return function() {
    const args = [...arguments];
    
    if(state[args]) {
      return state[args]; 
    } else {
      const value = fn.apply(this, args);

      state[args] = value;

      return value;
    }
  }
}

function add(a, b) {
  console.log('adding', a, b);
  return a + b; 
}

const memoizedAdd = memoize(add);

console.log(memoizedAdd(1, 2));
// adding 1 2
// 3