One 、 Case production

Achieve one , The function of converting numbers to uppercase Such as ： 123 turn One hundred twenty-three

stay nzh - npm (npmjs.com) Query on npm Document introduction to third-party modules

Find the corresponding package that may be used , Reference documents , Installation , Use

 npm Specific usage ：

Two 、npm brief introduction

npm Its full name is Node Package Manager, It's based on Node.js Package manager , Also the whole Node.js The most popular in the community 、 The package manager that supports the most third-party modules .npm The purpose of ：JavaScript It's easier for developers to share and reuse code .

1. nodejs = ECMAScript + Core module

2. Follow by yourself commonjs Write modules according to the specification , If you write a function module （ Date processing datejs, Digital processing numberjs）. If you can share these modules , Who wants to develop related functions in the future , Take the developed module directly and use it , There is no need to develop by yourself . There is a website on the internet dedicated to collecting such toolkits .npm Chinese document | npm Chinese net .

3. If we want to use the package in this website , Then we need to use a function , be called npm.

Official website ：npm Chinese document | npm Chinese net

md5 - npm

npm Can be used to ：

• Allow users to obtain third-party packages and use

• Allow users to publish and share their own packages or command-line programs

npm install ：

npm No need to install separately . In the installation Node When , Will be installed together npm.

Execute the following command to view the locally installed npm Version number of .

npm -v

If you want to upgrade npm , It can be like this .cmd If the interactive mode is not prompted, the upgrade can be ignored

npm install npm --global

3、 ... and 、npm Experience

To install and use md5 Module as an example ：

1、 Under project directory , Carry out orders npm init, There will be one more package.json file ( This file 1、 Record project related information , Such as project name , Project version 2、 The third-party modules used in the project will be recorded later )

2、 Under project directory , Carry out orders npm install md5, At this time, you will start downloading online md5 This package , The download process requires patience , The waiting time depends on the network speed .

3、 Seeing the following code indicates that the download is complete ：

After downloading ： There is one more in the local project directory node_modules Folder , What we just downloaded md5 Packages and their related dependent packages are all in this folder . In the future, we need to download other packages during development , Will be downloaded in this folder .

4、 We build new JS The file should be consistent with node_modules Folders at the same level , Then reference the third-party module in the new file

5、 After downloading, you can import it into the project and use it ：

var md5 = require('md5');
console.log(md5("12345789"));

Run to get an encrypted string .