Preface:
nodejs main language background
Custom Modules
JavaScript is a language Reception
nodejs are also using our JavaScript language, even his engines are the chrome v8 engine, open source, so learning nodejs front-end for us, it is a very friendly thing
Background languages:
php
python
Java
nodejs advantage
1. Performance
After a professional who does not test: nodejs 86 times higher than the performance of php
nodejs run 1s php to run one and a half
It is to write a project: php 200 servers a server 20000, a total of 4,000,000
nodejs 3 servers it is 60,000;
Of course, this is not that bad php, after all, can become a well-known language background, how could so weak; moreover, nodejs short time, really old compared to the background of the language, there are still weaknesses
2. The front desk js fit more convenient
Currently: nodejs still play the role of a tool class time nodejs appear or short;
nodejs really at the front, setting off a frenzy, we also have a lot of choice;
instruction
Nodejs program running in the popup window + r cmd input
Switching letter d: (d to disk)
Cd into the directory directory name
Run the program node file name
Completion directory tab
Terminate the program ctrl + c
js in usable nodejs can use
Case: Date
var oDate=new Date()
console.log(oDate.getFullYear)
Case: Regular
var re = / d / g
console.log("stds".match(re));
We run through nodejs found something we print something printed on browsers
By nodejs set up a server:
nodejs write a server, others can gain access to;
http protocol: browsers and servers comply with the specification;
Http communication between server and browser, are achieved through http
Our server, the most important part, listen, that is to say, http sends a request to the server, then the server should receive such a request, this is the monitor;
The first step in creating our servers; (content written in our js file to)
var http = require("http");
var server = http.createServer (function (request, response) {// http.createServer () to create a server, the callback function parameter
// two parameters request callback request in the inside, response response (we all know that the variable parameter, you can write with the change)
console.log (request.url) // URL acquired the following parameter;
response.write ( "123"); // data in response to a browser Response.Write ()
response.end (); // finished each response, we need to call this method to end response
})
server.listen (8080) // parameter is the port listening
This is the initial creation process