simple memoize sample

memoize_example.js

const memoize = (fn) => {
  const cache = {}
  return (...args) => {
    const key = args.toString()
    
    if(cache[key] == undefined){
      cache[key] = fn(...args)
    }
    
    return cache[key]
  }
}

let x = (num, num2) => num + 10 + num2

x = memoize(x) //Either mutate original function to memoized or could create memoized_x variable

var y = x(1,3)
console.log(y)