webpack打包代碼：

webpack runoob1.js bundle.js

會(huì)報(bào)錯(cuò)：

WARNING in configuration
The 'mode' option has not been set, webpack will fallback to 'production' for this value. Set 'mode' option to 'development' or 'production' to enable defaults for each environment.
You can also set it to 'none' to disable any default behavior. Learn more: https://webpack.js.org/configuration/mode/

報(bào)錯(cuò)圖片如下：

解決方法：

webpack4.0對(duì)語法要求更加嚴(yán)格，需要指定的相關(guān)信息，輸入的打包代碼應(yīng)該修改為：

webpack runoob1.js --output-filename bundle.js --output-path . --mode development

運(yùn)行結(jié)果如下：

問題解決！