vue 3.0安装步骤

1、安装webpack相关命令：npm install webpack -g；npm install webpack-cli -g

2、安装vue脚手架：npm install -g @vue/cli；或者yarn global add @vue/cli

3、安装vue项目：vue create test

4、跑项目：npm run serve；或者yarn serve

具体遇到的坑如下：

1、全局安装webpack，执行命令npm install webpack -g

全局安装webpack-cli，执行命令npm install webpack-cli -g
使用查看webpack版本的命令webpack -v(小写)
使用npm报错

npm ERR! code EPERM
npm ERR! syscall open
npm ERR! path C:\Program Files\nodejs\node_cache\_cacache\tmp\fc971ce3
npm ERR! errno -4048
npm ERR! Error: EPERM: operation not permitted, open 'C:\Program Files\nodejs\node_cache\_cacache\tmp\fc971ce3'
npm ERR! [OperationalError: EPERM: operation not permitted, open 'C:\Program Files\nodejs\node_cache\_cacache\tmp\fc971ce3'] {
npm ERR! cause: [Error: EPERM: operation not permitted, open 'C:\Program Files\nodejs\node_cache\_cacache\tmp\fc971ce3'] {
npm ERR! errno: -4048,
npm ERR! code: 'EPERM',
npm ERR! syscall: 'open',
npm ERR! path: 'C:\\Program Files\\nodejs\\node_cache\\_cacache\\tmp\\fc971ce3'
npm ERR! },
npm ERR! isOperational: true,
npm ERR! errno: -4048,
npm ERR! code: 'EPERM',
npm ERR! syscall: 'open',
npm ERR! path: 'C:\\Program Files\\nodejs\\node_cache\\_cacache\\tmp\\fc971ce3'
npm ERR! }
npm ERR!
npm ERR! The operation was rejected by your operating system.
npm ERR! It's possible that the file was already in use (by a text editor or antivirus),
npm ERR! or that you lack permissions to access it.
npm ERR!
npm ERR! If you believe this might be a permissions issue, please double-check the
npm ERR! permissions of the file and its containing directories, or try running
npm ERR! the command again as root/Administrator.

解决方案参考：https://www.cnblogs.com/qdjl/p/9481720.html

删除在C:\Users\{账户}\下的.npmrc文件

 webpack -v报错

webpack : 无法加载文件 C:\Users\lx\AppData\Roaming\npm\webpack.ps1，因为在此系统上禁止运行脚本。有关详细信息，请参阅 https:/go.microsoft.com/fwlink/?LinkID=13517
0 中的 about_Execution_Policies。
所在位置 行:1 字符: 1
+ webpack -v
+ ~~~~~~~
+ CategoryInfo : SecurityError: (:) []，PSSecurityException
+ FullyQualifiedErrorId : UnauthorizedAccess

解决方案参考：https://blog.csdn.net/weixin_46449470/article/details/107583652

 以管理员身份运行vs code

执行命令：get ExecutionPolicy，显示Restricted，表示状态是禁止的

执行命令：set ExecutionPolicy RemoteSigned

再执行命令：get ExecutionPolicy,就显示RemoteSigned

2、全局安装vue-cli3.0对应的新命令：npm install -g @vue/cli 或 yarn global add @vue/cli

yarn与npm对比参考：https://blog.csdn.net/qq_27674439/article/details/93976115

查看vue-cli3.0版本号：vue -version(小写)，或者vue -V(大写)