Question

MY-module.js

function cube(x) {
  return x * x * x;
}
const foo = Math.PI + Math.SQRT2;
export { cube, foo };

app.js

import React from 'react';
import ReactDOM from 'react-dom';
import {cube} from './my-module';

的console.log（立方体（2））; 没有错误，但显示，似乎import无效。 stackoverflow，无需更多详细信息，代码已显示我的含义，请不要强制我们添加更多详细信息。

"ReferenceError: cube is not defined
    at eval (eval at 35 (http://localhost:8080/build/bundle.js:84:1), <anonymous>:1:1)
    at Object.35 (http://localhost:8080/build/bundle.js:84:1)
    at __webpack_require__ (http://localhost:8080/build/bundle.js:20:30)
    at Object.34 (http://localhost:8080/build/bundle.js:71:18)
    at __webpack_require__ (http://localhost:8080/build/bundle.js:20:30)
    at http://localhost:8080/build/bundle.js:63:18
    at http://localhost:8080/build/bundle.js:66:10"

webpack.config.js

module: {
    loaders: [
      {
        test: /\.js$/,
        loaders: ['babel-loader'],
        exclude: /(node_modules)/
      },

.babelrc

{
  "presets": [
    "es2015",
    "react",
    "stage-0"
  ],
  "plugins": [
    "transform-react-jsx"
  ],
  "retainLines": true,
  "sourceMaps": "both",
  "ignore": [
    "*.css"
  ]
}

Answer 1

尝试import { cube } from './my-module'

执行import cube时，您正在寻找默认导出

Answer 2

我尝试使用您提供的信息重现错误但我不能。

具体来说，我创建了这个简单的项目，一切都按预期工作。

<强>的package.json

{
  "name": "dummy-react",
  "version": "1.0.0",
  "description": "",
  "main": "app.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "babel": "^6.23.0",
    "babel-core": "^6.26.0",
    "babel-loader": "^7.1.2",
    "babel-plugin-transform-react-jsx": "^6.24.1",
    "babel-preset-es2015": "^6.24.1",
    "babel-preset-react": "^6.24.1",
    "babel-preset-stage-0": "^6.24.1",
    "react": "^16.2.0",
    "react-dom": "^16.2.0",
    "webpack": "^3.10.0"
  }
}

<强> .babelrc

{
  "presets": [
    "es2015",
    "react",
    "stage-0"
  ],
  "plugins": [
    "transform-react-jsx"
  ],
  "retainLines": true,
  "sourceMaps": "both",
  "ignore": [
    "*.css"
  ]
}

<强> webpack.config.js

var webpack = require('webpack')

module.exports = {
  entry: './app.js',
  output: {
    filename: 'bundle.js'
  },
  module: {
    loaders: [
      {
        test: /\.js$/,
        loaders: ['babel-loader'],
        exclude: /(node_modules)/
      }
   ]
  }
}

我-module.js

function cube(x) { return x * x * x; } const foo = Math.PI + Math.SQRT2; export { cube, foo };

<强> app.js

import React from 'react' import ReactDOM from 'react-dom' import {cube} from './my-module' console.log(cube(2)) ReactDOM.render( <h1>Hello, World!</h1>, document.getElementById('root') );

<强>的index.html

<html> <head> </head> <body> <div id="root"></div> <script src="./bundle.js"></script> </body> </html>

所以问题可能不在你提供的代码中。

为什么我的Babel导入不起作用？

2 个答案: