let deepCache = {}; function Fib(num){ if(num == 1 || num == 2) return 1; // 如果计算过直接返回 if(deepCache[num]) return deepCache[num]; return deepCache[num] = Fib(num - 1) + Fib(num - 2); } console.time(); console.log(Fib(7)); // 354224848179262000000 console.timeEnd(); // 0.145751953125ms