webpack4.0.1安装问题和webpack.config.js的配置变化

The CLI moved into a separate package: webpack-cli. Please install 'webpack-cli' in addition to webpack itself to use the CLI. -> When using npm: npm install webpack-cli -D -> When using yarn: yarn add webpack-cli -D

webpack4.0.1安装问题，提示：
The CLI moved into a separate package: webpack-cli.
Please install 'webpack-cli' in addition to webpack itself to use the CLI.
-> When using npm: npm install webpack-cli -D
-> When using yarn: yarn add webpack-cli -D
解决方案：
一、webpack -v 版本号出不来
提示：
The CLI moved into a separate package: webpack-cli.
Please install 'webpack-cli' in addition to webpack itself to use the CLI.
-> When using npm: npm install webpack-cli -D
-> When using yarn: yarn add webpack-cli -D

意思是CLI被移动到了一个专门的包 webpack-cli里了。
请安装webpack-cli 的除了webpack本身使用cli
当用npm时，使用npm install webpack-cli -D安装。
当用yarn时，使用yarn add webpack-cli -D安装。

解决办法：全局安装webpack-cli

npm install webpack-cli -g

就能提示出版本号了。