Node. js Learning (4) ---- Node Module

Before writing a Node application, you must first learn the Node modules and packages. Modules and packages are the basic units of applications. A Node. js file is a module, which may be Javascript code, JSON, or compiled C/C ++ extensions.

var count=0;exports.next=function(){return count++;}

Instance:

var name;exports.setName=function(thyName){name=thyName;};exports.sayHello=function(){console.log("Hello "+name);};

Create getmodule. js call module. js

var module=require('./module');module.setName('Public');module.sayHello();

The final running result is: Hello Public

var hello1=require('./module');hello1.setName('Tom 1');var hello2=require('./module');hello2.setName('Tom 2');hello1.sayHello();

Running result: Hello Tom 2

The results show that the former is overwritten by the latter, so the final result is determined by the latter.

Function Hello () {var name = 'horjuna '; this. setName = function (thyName) {name = thyName ;}; this. sayHello = function () {console. log ('hello' + name) ;};} exports. hello = Hello;

In this case, we need to get the Hello object through require ('./singleobject'). Hello in other files,

var Hello=require('./singleobject').Hello;var hello=new Hello();hello.setName('Module');hello.sayHello();

Function Hello () {var name = 'horjuna '; this. setName = function (thyName) {name = thyName ;}; this. sayHello = function () {console. log ('hello' + name) ;};} module. exports = Hello;

Gethello. js

var Hello=require('./hello');var hello=new Hello();hello.setName('Module');hello.sayHello();

Note that the only change in the module is to change exports. Hello to module. exports. When this module is referenced externally, its interface object is the Hello object to be output, rather than the original exports.