Javascript React can';找不到

Javascript React can';找不到,javascript,reactjs,webpack,Javascript,Reactjs,Webpack,index.js: import react from 'react'; import {render} from 'react-dom'; render( <h1>Hello World!</h1>, document.getElementById('root') ); 网页包配置: var webpack = require('webpack'); var packages = require('./package.json'); var path

index.js

import react from 'react';
import {render} from 'react-dom';

render(
    <h1>Hello World!</h1>,
    document.getElementById('root')
);
网页包配置:

var webpack = require('webpack');
var packages = require('./package.json');
var path = require('path');

module.exports = {
    entry: {
        main: './src/index.js',
        vendor: Object.keys(packages.dependencies)
    },
    output: {
        filename: '[name].js',
        path: path.resolve(__dirname, 'dist')
    },

    plugins: [
        new webpack.optimize.CommonsChunkPlugin({
            name: 'vendor' // Specify the common bundle's name.
        })
    ],

    devtool: "cheap-eval-source-map",

    devServer: {
        contentBase: path.join(__dirname, "dist"),
        publicPath: '/',
        port: 9000
    },

    module: {
        rules: [
            {
                test: /\.js?$/,
                use: [ 'babel-loader', ],
                exclude: /node_modules/
            }
        ]
    }
};
网页包输出:

Chrome开发输出:


将导入的React类命名为以大写字母开头是至关重要的。第一行应该是:
importreact from'React'。这是因为所有JSX标记都将由Babel转换为类似于
React的东西。createElement(..)
React
不存在。这正是控制台输出告诉您的。

以大写字母开头命名导入的React类非常重要。第一行应该是:
importreact from'React'。这是因为所有JSX标记都将由Babel转换为类似于
React的东西。createElement(..)
React
不存在。控制台输出会告诉你什么。

你是在main.js文件中导入还是需要它?@PatrickHund更新了问题import
React
not
React
你是在main.js文件中导入还是需要它?@PatrickHund更新了问题import
React
not
React
但是在chrome dev中很愚蠢输出它说
React
意味着我做对了。。。。这就是为什么它抛出了我,但在chrome-dev的输出中,它愚蠢地说,
React
暗示我做对了。。。。这就是为什么它把我甩了
var webpack = require('webpack');
var packages = require('./package.json');
var path = require('path');

module.exports = {
    entry: {
        main: './src/index.js',
        vendor: Object.keys(packages.dependencies)
    },
    output: {
        filename: '[name].js',
        path: path.resolve(__dirname, 'dist')
    },

    plugins: [
        new webpack.optimize.CommonsChunkPlugin({
            name: 'vendor' // Specify the common bundle's name.
        })
    ],

    devtool: "cheap-eval-source-map",

    devServer: {
        contentBase: path.join(__dirname, "dist"),
        publicPath: '/',
        port: 9000
    },

    module: {
        rules: [
            {
                test: /\.js?$/,
                use: [ 'babel-loader', ],
                exclude: /node_modules/
            }
        ]
    }
};