在express框架中运用import export

在新搭建的基于node.js的express框架时，不能直接运用import/export，否则会报错如下：

import mysql from 'mysql';
^^^^^^

SyntaxError: Unexpected token import
    at new Script (vm.js:51:7)
    at createScript (vm.js:136:10)
    at Object.runInThisContext (vm.js:197:10)
    at Module._compile (internal/modules/cjs/loader.js:618:28)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:665:10)
    at Module.load (internal/modules/cjs/loader.js:566:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:506:12)
    at Function.Module._load (internal/modules/cjs/loader.js:498:3)
    at Module.require (internal/modules/cjs/loader.js:598:17)
    at require (internal/modules/cjs/helpers.js:11:18)
[nodemon] app crashed - waiting for file changes before starting...

所以需要在入口文件里面导入babel依赖
1* yarn add babel-register babel-preset-env --save-dev
2* 在./bin/www文件的第一行添加如下代码

require('babel-register')({
  presets: ['env']
});

3* npm start启动项目，已可以正常运行了

> nodemon ./bin/www

[nodemon] 1.18.7
[nodemon] to restart at any time, enter `rs`
[nodemon] watching: *.*
[nodemon] starting `node ./bin/www`

在express框架中运用import export

浏览过的版块