目录结构

index.html

src/index.js

let a = 1;console.log(a);

安装依赖

npm init -ycnpm install -g babel-clicnpm install --save-dev babel-preset-es2015 babel-cli

新建.babelrc

{    "presets":[        "es2015"    ],    "plugins":[]}

运行转化

babel src/index.js -o dist/index.js

dist/index.js

"use strict";var a = 1;console.log(a);

运行index.html

简化打包命令//package.json

"scripts": {    "build": "babel src/index.js -o dist/index.js"  },

直接运行

npm run build