ES6 in the browser: Uncaught SyntaxError: Unexpected token import

问题

I\'m new to ES6 (ECMAScript 6), and I\'d like to use its module system in the browser. I read ES6 is supported by Firefox and Chrome, but I\'m getting the following error using export

Uncaught SyntaxError: Unexpected token import

I have a test.html file

<html>
    <script src=\"test.js\"></script>
<body>
</body>
</html>

and a test.js file

\'use strict\';

class Test {

    static hello() {
        console.log(\"hello world\");
    } 
}

export Test;

Why?

回答1:

Many modern browsers now support ES6 modules. As long as you import your scripts (including the entrypoint to your application) using <script type="module" src="..."> it will work.

Take a look at caniuse.com for more details: https://caniuse.com/#feat=es6-module

回答2:

You can try ES6 Modules in Google Chrome Beta (61) / Chrome Canary.

Reference Implementation of ToDo MVC by Paul Irish - https://paulirish.github.io/es-modules-todomvc/

I've basic demo -

//app.js
import {sum} from './calc.js'

console.log(sum(2,3));

//calc.js
let sum = (a,b) => { return a + b; }

export {sum};

<html> 
    <head>
        <meta charset="utf-8" />
    </head>

    <body>
        <h1>ES6</h1>
        <script src="app.js" type="module"></script>
    </body>

</html>

Hope it helps!

回答3:

Unfortunately, modules aren't supported by many browsers right now.

This feature is only just beginning to be implemented in browsers natively at this time. It is implemented in many transpilers, such as TypeScript and Babel, and bundlers such as Rollup and Webpack.

Found on MDN

回答4:

it worked for me adding type="module" to the script importing my mjs:

<script type="module">
import * as module from 'https://rawgit.com/abernier/7ce9df53ac9ec00419634ca3f9e3f772/raw/eec68248454e1343e111f464e666afd722a65fe2/mymod.mjs'

console.log(module.default()) // Prints: Hi from the default export!
</script>

See demo: https://codepen.io/abernier/pen/wExQaa

来源：https://stackoverflow.com/questions/41722621/es6-in-the-browser-uncaught-syntaxerror-unexpected-token-import

标签

javascript

html

ecmascript-6

module

es6-modules