Question

我是ES6的新手，请原谅我，如果这是一个重复的问题。正如标题所述，我目前正在收到错误：

未捕获的SyntaxError：意外的令牌导入

显然，对象Person尚未成功导入以在app.js文件中使用。

我查看了网络上的示例代码，但仍无法正常工作。我怀疑它与webpack.config.js设置有关。

我也尝试使用let person = require("./modules/Person");，但它不起作用。

请有任何想法？他们将非常感激。

我在下面提供了代码摘录：

的src / JS /模块/ person.js

class Person {

    constructor(name, jobtitle, sex){
        this.name = name;
        this.jobtitle = jobtitle;
        this.message = document.getElementById("message").html;
        this.sex = sex;
    }

    Greet(){
        console.log("Hello, my name is "+ this.name + " and i am a " + sex);
    }

    EchoOccupation(){
        console.log("I am a "+ this.jobtitle);
    }

    EchoMessage(){
        console.log("The message is "+ this.message);
    }
}

module.exports = Person;

的src / JS / app.js

import { Person } from './modules/person';

let vic = new Person("Fred", "Web Developer", "male");
vic.Greet();
vic.EchoOccupation("Web Developer");

webpack.config.js

var path = require("path"),
    watchBabel = require("watch-babel"),
    srcJsDir = "./src/js/",
    srcDestJsDir = "dist/assets/js/",
    options = { glob: "src/*.js" },
    watcher = watchBabel(srcJsDir, srcDestJsDir, options);

watcher.on("ready", function() { 
    console.log("ready"); 
}).on("success", function(filepath) {
    console.log("Transpiled ", filepath);
}).on("failure", function(filepath, e) {
    console.log("Failed to transpile", filepath, "(Error: ", e);
}).on("delete", function(filepath) {
    console.log("Deleted file", filepath);
});

module.exports = {

    entry: [srcJsDir + "/app.js"],
    output:  {
        path: srcDestJsDir,
        filename: "app.js"
    },
    watch: true,
    devServer: {
        inline: true,
        port: 8000
    },
    module: {
        loader : [
            { 
                test: /\.js$/,
                exclude: "/node_modules/",
                loaders: ['babel', 'watch-babel'],
                query: {
                    presets: ['es2015'],
                    plugins: ['babel-plugin-uglify']
                } 
            },
        ]
    },
    resolveLoader: {
        root: path.join(__dirname, 'node_modules/')
    }
};

的index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8" />
    <title>im loving es6</title>
    <link href="/src/css/frameworks/bootstrap.min.css" />
</head>
<body> 
    <header></header>
    <main>
        <div class="container">
            <div class="row">
                <div class="col-xs-12">
                    <article>
                        <section> 
                            <div id="app"></div>
                            <div id="message">Hello this is my message!</div>
                        </section>
                        <aside></aside>
                    </article>
                </div>
            </div>
        </div>
    </main>
    <footer></footer>
    <script type="text/javascript" src="/dist/assets/js/app.js"></script>
</body>
</html>

Answer 1

发生错误是因为从person.js导出的模块没有Person属性。

您可以通过进行三项更改来解决此问题：

<强>的src / JS /模块/ person.js

class Person {
  ...
}

// Set the Person class as the object exported from this module
export default Person;

<强>的src / JS / app.js

// Import the Person class
import Person from './modules/person';

<强> webpack.config.js

...
module: {
  // Rename the 'loader' property to 'loaders'
  loaders: [
    ...
  ]
}

您可以在此处找到有关import的更多信息：ES6 import

Webpack / Babel ES6错误：未捕获的SyntaxError：意外的令牌导入

1 个答案: