var fibonacci = function() { var memo = []; var fiboFunc = function(num){ var result; if(num in memo) { return memo[num]; } else { if(num==0 || num==1) { memo[num] = num; return num; } else { result = fiboFunc(num-1)+fiboFunc(num-2); memo[num] = result; return result; } } }; return fiboFunc; } var fibo = new fibonacci() console.log(fibo(5)); console.log(fibo(7))