匿名函数还是要创建的吧.
手动的话试试这两中模式:
1. 串行版本

(function next(i, len, callback) { if (i < len) { async(arr[i], function (value) { arr[i] = value; next(i + 1, len, callback); }); } else { callback(); } }(0, arr.length, function () { // All array items have processed. }));

或者并行版本

(function (i, len, count, callback) { for (; i < len; ++i) { (function (i) { async(arr[i], function (value) { arr[i] = value; if (++count === len) { callback(); } }); }(i)); } }(0, arr.length, 0, function () { // All array items have processed. }));

来自于 http://nqdeng.github.io/7-days-nodejs/#6.2