Getting to know Node JS

One, NVM

1. nvmCan switch nodeversion management node, download address https://github.com/coreybutler/nvm-windows/releases, as follows:

• nvm-noinstall.zip: Green free installation version, but it needs to be configured when using it.
• nvm-setup.zip: Installed version, recommended

2. nvm Common commands are as follows:

• nvm listSee all current nodeversions
• nvm install v10.13.0 Install the specified version
• nvm use -delete-prefix 10.13.0 Switch to the specified version

Two, NodeJS and JS

1. ECMAScript,As follows:

• It defines the syntax, writing JavaScriptand nodejSmust comply
• Variable definition, loop, judgment, function
• Prototype and prototype chain, scope and closure, asynchronous
• Can not operate DOM, you can not monitor clickevents, you can not send ajaxrequest
• Can not process httpthe request, the file can not operate
• Only ECMAScript, can hardly do any actual projects

2. JavaScript,As follows:

• Use ECMAScriptsyntax specification, plus web APIindispensable
• DOMOperation, BOMoperation, event binding, Ajaxetc.
• Combine the two to complete any operation on the browser side

3. nodeJS,As follows:

• Use ECMAScriptsyntax specification, plus nodejS APIindispensable
• Processing http, processing files, etc., learninghttp://nodejs.cn/api/assert.html
• Combination of both, to complete the serverend of any operation

4. The summary is as follows:

• ECMAScript Is a grammar specification
• nodeJS = ECMAScript + nodeJS API

Three, server side and front-end development

1. server The difference between front-end and front-end development is as follows:

• Service stability
• Consider memory and CPU(optimization, expansion)
• Logging
• Safety
• Cluster and service split

2. Service stability is as follows:

• server The end may be subject to various malicious attacks and misoperations
• A single client can hang up unexpectedly, but the server cannot
• PM2 Wait for the process

3. Consider memory and CPU(optimization, expansion) as follows:

• The client exclusively a browser, memory, and CPUnot a problem
• serverThe end has to carry a lot of requests, CPUand memory is a scarce resource
• streamWrite the log, using redisdepositsession

4. The log records are as follows:

• The front end will also participate in writing the log, but it is only the originator of the log and does not care about the follow-up
• server The end needs to record logs, store logs, and analyze logs. The front end does not care
• There are multiple logging methods and how to analyze the logs

5. Security, as follows:

• server The end must be ready to receive various malicious attacks at any time, while the front end must be much less
• For example, unauthorized operation, database attacks, etc.
• Login authentication, prevent XSSattacks and sqlinjection

6. The cluster and service are split as follows:

• Product development is fast, traffic may increase rapidly
• Carry large traffic by expanding machines and service splitting
• Support service splitting in design