1·安装n插件
npm install -g n --force
--------->
npm WARN using --force I sure hope you know what you are doing.
C:\Users\cc\AppData\Roaming\npm\n -> C:\Users\cc\AppData\Roaming\npm\node_modules\n\bin\n
+ n@2.1.8
added 1 package in 0.359s
2·升级至在最新版本
n stable
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install : node-v9.0.0
3·升级至指定版本
n v9.0.0
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install : node-v9.0.0