1.首先建一个math.js

exports.add = function(a, b){    return a + b;}exports.sub = function(a, b){    return a - b;}exports.mul = function(a, b){    return a * b;}

2.然后建一个app.js 引人math.js

var math = require('./math');console.log(math);//{ add: [Function], sub: [Function], mul: [Function] }var command = process.argv[2];var a = Number(process.argv[3]);var b = Number([process.argv[4]]);var value = math[command](a, b);console.log(value);//node app.js mul 1 2 结果为2

CMD运行

node app.js add 1 2 //3node app.js sub 1 2 //-1node app.js mul 1 2 //2