Mac uses nvm to manage node version switching

Install

1. Use npm to install n globally (since you need to write files, you use sudo to elevate the operation and use administrator privileges to execute the command)
   sudo npm i -g n
2. After the progress bar runs out, check whether the installation is complete.
   n -V

Install and switch node versions

1. List all node versions
   n ls
2. install a version
   sudo n xx.xx.x (xx.xx.x 为要安装的版本号)
   
3. Install the latest versionsudo n lastest
4. Install the latest stable versionsudo n stable
   
5. Switch the node version (enter the command and select the up and down keyboard to confirm)
   n
6. Delete a versionn rm xx.xx.x
7. Use a version to run the scriptn use xx.xx.x a.js