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req.paramsReturn route param. The stuff before query param -- '?'Node:router.get('/yomama/:something', function(req, res, next) { console.log(req.params.something);});URI:http://localhost:3000/fibonacci/yomama/3wafwa?node=xxxOutput:3waf

Create Server调用 http http.createServer(function(req,res){ ... }).listen(portNum); function用于处理client请求并返回response function每次request都会被运行 var http = require('http');var fs = require('fs');var url = require('url'); // 创建服务器http.createServer..

GET request解析url -- url.parse e.g.http://localhost:3000/user?name=Charlie var http = require('http');var url = require('url');http.createServer(function(req, res){ // 获取url参数列表 var params = url.parse(req.url, true).query; console.log.

fs 同时支持sync & asynce.g. readdirSync vs. readdir获取文件列表fs.readdir(dir_name, function(err,files){})目录名 回调函数 error对象 files数组 fs.readdir('.', function(err,files){ // 读取当前目录文件列表并打印 console.log(files);})获取文件元数据fs.stat(file_p..

__filename当前正在执行的脚本的绝对路径__dirname当前执行脚本所在的目录setTimeout(cb, ms)在ms毫秒后执行一次函数(cb)clearTimeout(t)取消Timeout，tsetInterval(cb, ms)每ms毫秒后执行一次函数(cb)clearInterval(cb, ms)取消intervalconsole控制台Process当前进程，一个与操作系统的简单接口...

文件模块一一对应引入模块require用于从外部获取一个模块 引入当前文件夹内的hello.js var hello = require('./hello');导出模块exports用于把对象公开 公开文件中的 'world' function：【hello.js】exports.world = function() {...} 使用world：require('hello'); hello.world() //先import文件，再使用function 直接.

An abstract classthat is widely implemented and used in Node.jsTypes Readable- 可读操作。 Writable- 可写操作。 Duplex- 可读可写操作. Transform- 操作被写入数据，然后读出结果 Stream Events data- 当有数据可读时触发。 end- 没有更多的数据可读时触发。 error- 在接收和写入过程中发生错误时...

该类用来创建一个专门存放二进制数据的缓存区创建 Buffer 类 const buf1 = Buffer.alloc(10); //创建长度为10的缓存区 写入缓冲区 len = buf.write("www.runoob.com"); //返回实际写入的大小 读取缓存区 buf.toString('utf8'） //以utf-8返回字符串 转json buf.toJSON() // 返回 JSON 对象 长度 buf.length; ..

Only object in event class: Event.EventEmitter Emitter can both listen and emit eventsMethods

> npm i typescript> tsc test.ts> node test.jsType Systemany: no type number: double precision (64-bit) floating point null vs. undefined:A variable initialized with undefined means that the variable has no value or object assigned t..

asynchronous programming handle multiple tasks at the same time kip the current operation and move to the next line of the codeSyntaxvar promise = new Promise(function(resolve, reject){// our logic goes here ..});If the function’s response is .

SetupCreate project folder cd. into the folder and run "npm i -g express-generator" to install project generator globally run "express" to generate project in the project folder option "--view=hbs" sets up the view template run "npm install" instal

basic es6 classdefinitionclass Note { constructor(key, title, body) { this._key = key; this._title = title; this._body = body; } get key() { return this._key; } get title() { return this._title; } set title(

reqreq.url: host名之后的所有内容. e.g. http://localhost:4200/url --> req.url = /url req.method: http method. i.e. GET, POST, PUT DELETEaccessing req body dataNode sends its data using stream API, that is, inchunks.Therefore,the best way to access dat..

<script>Used to included the javascript code in HTML.Basic format:<script src= "scripts/digital_clock.js"></script>moduleIf you have used modules in your code, i.e. import, export directives, made the script type as module..

ArityUnary: accepts one single expression. e.g. -x Binary: accepts exactly 2 expressions. e.g. a*b Ternary: combines 3 expressions into 1 expression, only one. i.e. ?: -- conditional operatorlval: 等号左边的variable. e.g. variables, object properties, arra

Anexpressionis a phrase of JavaScript that can beevaluatedto produce a value.Primary ExprDoNOTinclude any simpler expressionsconstant orliteralvalues Language keywords (reserved words) Variable referencesConstant and Literals1.23 ...

Semi-colon -- NOT requiredGarbage Collection (GC) -- Automatic Objected Oriented Comments// /* */Primitive TypesAll rpimitive types are immutablenumbers strings Boolean null undefined symbol (ES6)** Null & undefined have no meth.

letlet i, sum;Declare and assign an initial value to your variables:let message = "hello";let i = 0, j = 0, k = 0;let x = 2, y = x*x; // Initializers can use previously declared variablesIf you don’t specify an initial value, the value is "un

ImplicitExplicitUse theBoolean(),Number(), andString()functions Note: toString() is an alternative for String() among most objects other than null or undefined Number()only works for base-10 integers and does not all...

A global objectis a javascript object. Its properties defines the globally defined identifiers Created when the Javascript interpreter startsThe default set of propertiesConstants: undefined, Infiity, NaN, etc. Functions: isNan(), parseInt(), eva..

"null == undefined" returns true "null ===undefined" returns false Both null and undefined are falsy Both have no properties or methodsNullLanguage keyword typeof("null") = "object" -- i.e. null is actually a genericobject Therefore can be us...

核心模块之外，npm & packages link modules together.Common.js package 规范Common.js是JS在后端应用的一个同步规范, 解决了缺乏模块系统、标准库较少、没有标准接口、缺乏包管理系统等问题，让JS成为了一个可以进行大型应用开发的语言Common.js 的包规范即 require**webpack、nodejs、npm 全都是 implement common.js 规范的Package 结构pack..

Express:a “minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications.”