定义一个Node模块：currency.js
var canadianDollar = 0.91;function roundTwoDecimals(amount) { ???return Math.round(amount * 100) / 100;}exports.canadianToUS = function (canadian) { ???return roundTwoDecimals(canadian * canadianDollar);}exports.USToCanadian = function (us) { ???return roundTwoDecimals(us / canadianDollar);}引入一个模块：
下面的test-currency.js中的代码，它require了currency.js模块：
var currency = require(‘./currency‘);console.log(‘50 Canadian dollars equals this amount of US dollars:‘);console.log(currency.canadianToUS(50));console.log(‘30 US dollars equals this amount of Canadian dollars:‘);console.log(currency.USToCanadian(30));
输出结果：
50 Canadian dollars equals this amount of US dollars:45.530 US dollars equals this amount of Canadian dollars:32.97
Node.js 定义和引用模块
原文地址：http://www.cnblogs.com/sumuzhe/p/7465775.html