var module = {
  exports: {}
};

(function(module, exports) {
  exports.multiply = function (n) {
      return n * 1000 
   };
}(module, module.exports))

var f = module.exports.multiply;
f(5) // 5000

// 引入
const fs = require('fs')

// 导出
exports.fs = fs
module.exports = fs

// 引入
import fs from 'fs'
import {readFile} from 'fs'

// 导出
export default fs
export const fs
export function readFile
export {readFile, read}