08:00:00.000 function cached (fn) {               var cache = Object.create(null);               return (function cachedFn (str) {                 var hit = cache[str];                 return hit || console.log('hit no cache') || (cache[str] = fn(str))               })             }08:00:00.000 function a() {               return 'a';             }08:00:00.000 undefined08:00:00.000 ff = cached(a)08:00:00.000 ƒ cachedFn(str) {    var hit = cache[str];    return hit || console.log('hit no cache') || (cache[str] = fn(str))  }08:00:00.000 ff('ccc')17:01:00.294 VM63691:5 hit no cache17:01:00.294 "a"17:01:00.294 ff('ccc')17:01:00.294 "a"17:01:00.294 ff('ddd')17:02:26.595 VM63691:5 hit no cache17:02:26.595 "a"

chrome 控制台的输出