javascript 新手求教代码解释

Question

 if (typeof define === 'function' && define.amd)
      define(['jquery'], factory);
    else if (typeof exports === 'object')
      factory(require('jquery'));
    else
      factory(jQuery);

这段代码里 define 和 exports 分别是什么？ 是js的内置变量？

Answer 1

http://stackoverflow.com/questions/16950560/what-is-define-function-in-javascript
http://stackoverflow.com/questions/16383795/difference-between-module-exports-and-exports-in-the-commonjs-module-system