1-3 nodejs installation list configuration and project environment

Module installation and operation steps

（1） Based on npm Install third party modules
1. In a local project , Create a file package.json file ; This file is used to record the information of the third-party modules we installed . Or configure some executable script commands .
be based on yarm The installation will generate a configuration list by default , Only information , But there is no manual generated complete .
So recommend npm install ：
command ：npm init -y
The generated list is as follows ：

{
  "name": "c_web",		// Module name 
  "version": "1.0.0",		// Version number 
  "description": "",		// Module description 
  "main": "index.js",		// Module main entry file 
  "scripts": {					// Executable script . Here is an example ：
    "dev": "webpack --mode development",			// Packaging in the development environment 
    "build": "webpack --mode production"				// Packaging in a production environment 
  },
  
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {				// Production depends on 
    "jquery": "^3.4.1"
  },
    "devDependencies":{		// Development depends on 
	  
  }
}

 Its main function is , When the team assists in development , Others pull items from remote warehouses , Know which modules are installed in the project , according to package.json Of 
 The list can be installed by yourself .（ Because the general project upload is not upload node_modules Of , Because there are too many dependent libraries ）
 Be careful ： Configuration list , Do not appear in Chinese , May not be able to recognize .

（2） install
Development depends on ： Only the third-party modules that are relied on in the project development phase
npm install xxx --save Save to the production dependency of the configuration list

Production depends on ： When the project is deployed and implemented , Also need to rely on third-party modules
npm install xxx --save dev Save to the development dependency of the configuration manifest
–dev perhaps --D It's all about installing components into development dependencies

（3） When deploying, run the environment

When you get a new project , And pull it down from the warehouse . When there is no dependency , Just execute the order ：
npm install perhaps yarn install that will do .

because npm It will automatically retrieve whether there is... In the directory package.json file , And install in sequence according to the list in the document .
without , Then nothing is installed .