node. JS Summary

1.Node is a working environment for JavaScript based on the Chrome V8 engine. node. JS uses an event-driven, non-blocking I/O model to make it lightweight and efficient. Browsers are also the operating environment for JavaScript.

2. There is a security restriction in the browser environment and it is not allowed to invoke the underlying method. node allows the invocation of various underlying APIs.

Features of 3.node.js:

1> It is a JavaScript runtime environment

2> relies on the chrome V8 engine for code interpretation

3> Event Driver

4> non-blocking I/O

5> lightweight and scalable for real-time data interactive applications

6> single process, single thread

4.node is suitable for the development of high concurrency (high concurrency: Concurrently hosted capacity, non-blocking, dynamic allocation of space, pre-allocation of fixed space) projects. Typically used as a middle tier in large projects. (middle tier: calling interfaces to address high concurrency problems and performance issues with a large number of computational problems.) Middle-tier benefits: the front-end separation, is to better solve the coupling degree of the project, not waiting for each other, no longer depend on each other, join node this layer is actually for better decoupling. )

Disadvantages of 5.node:

Processing a large number of calculations can be slow. General calculations are given to the Java server for processing.

6. Package Manager NPM: Become the world's largest open source ecosystem. NPM is a node's package management repository, a Web site, or a command. (The company has a private NPM warehouse).

7.NPM (Package Manager) Cons:

1> package is synchronous download, very slow

2> is used in another project and needs to be downloaded again in another project.

node. JS Summary