vue运行npm run dev 出现错误！！原因是什么？

Question

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! vuedemo@1.0.0 dev: `cross-env NODE_ENV=development webpack-dev-server --open --hot`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the vuedemo@1.0.0 dev script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm WARN Local package.json exists, but node_modules missing, did you mean to install?

npm ERR! A complete log of this run can be found in:
npm ERR! C:\Users\Administrator\AppData\Roaming\npm-cache\_logs\2019-03-15T16_34_40_637Z-debug.log

Answer 1

先通过tnpm install安装npm包，安装完后，再执行npm run dev启动服务

Answer 2

上面提示了，翻译一下（package.json存在，但是 node_modules不存在，你的意思是安装吗？）这个意思是你没有安装依赖项,需要先安装依赖项。运行npm install进行安装。如果嫌npm慢可以使用yarn或者cnpm安装依赖，安装完毕就可以运行了npm start