Export-import in JavaScript --- SyntaxError: Cannot use import statement outside a module

Question

I am learning JavaScript today. I have created two files 'a.js' 'b.js' in the same directory.

a.js code

    export default class User {
    constructor(n) {
        this._a = n;
    }
}

export function f(n) {
    console.log("Funct");

}

b.js code:

import User, {f} from './a.js';

var u = new User("hey");

console.log(u, u._a);

f();

when I run node b.js, hits me up with this error like below:

(node:47205) Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension. /Users/rammurthys/Documents/Angular Tute/JS/b.js:1 import User, {f} from './a.js'; ^^^^^^

SyntaxError: Cannot use import statement outside a module at wrapSafe (internal/modules/cjs/loader.js:1055:16) at Module._compile (internal/modules/cjs/loader.js:1103:27) at Object.Module._extensions..js (internal/modules/cjs/loader.js:1159:10) at Module.load (internal/modules/cjs/loader.js:988:32) at Function.Module._load (internal/modules/cjs/loader.js:896:14) at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12) at internal/main/run_main_module.js:17:47

If I run node a.js, it throws error like below.

(node:47321) Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension. /Users/rammurthys/Documents/Angular Tute/JS/a.js:1 export default class User { ^^^^^^

SyntaxError: Unexpected token 'export' at wrapSafe (internal/modules/cjs/loader.js:1055:16) at Module._compile (internal/modules/cjs/loader.js:1103:27) at Object.Module._extensions..js (internal/modules/cjs/loader.js:1159:10) at Module.load (internal/modules/cjs/loader.js:988:32) at Function.Module._load (internal/modules/cjs/loader.js:896:14) at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12) at internal/main/run_main_module.js:17:47

I am using node v13.5.0. Executing this on VS code.

Please help me understand what am I missing. Thanks

The first line of the error message tells you two things you can do to fix this. Have you tried them? — Quentin
– Quentin, Commented Apr 6, 2020 at 13:50
The first line of the error message tells you two things you can do to fix this. If you don't like one, then try the other. — Quentin
– Quentin, Commented Apr 6, 2020 at 13:53
oh yes, renaming with .mjs works! thanks . I figure out why is that required. — RAMMURTY
– RAMMURTY, Commented Apr 6, 2020 at 13:58

RAMMURTY · Accepted Answer · 2020-04-06 14:03:34Z

2

renaming .mjs from .js did the trick. Thanks @Quentin!

.mjs is the one of the two ways to play around export-import javascript apart from require {} stuff.

Detailed explanation: https://medium.com/passpill-project/files-with-mjs-extension-for-javascript-modules-ced195d7c84a

answered Apr 6, 2020 at 14:03

RAMMURTY

611 silver badge9 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

VPaul · Accepted Answer · 2020-04-06 14:19:30Z

1

It's important to understand that NodeJS is not ES6. What you're trying to do is part of the ES6 spec. Not everything is available in NodeJS by default as of now that's why .mjs extension is required. Once ES6 finalizes things in near future, NodeJS will be able to add the support as well.

I wouldn't recommend using .mjs extension. It would be better go with a transpiler like Babel. Babel compiles your ES6 code into NodeJS without having to change the extension of your file.

Similar info can be found here: https://medium.com/the-node-js-collection/an-update-on-es6-modules-in-node-js-42c958b890c

answered Apr 6, 2020 at 14:19

VPaul

1,02311 silver badges24 bronze badges

1 Comment

Dan D Over a year ago

ES6 is now the common thing, using ES6 .mjs is recommended

Michele Delle Donne · Accepted Answer · 2023-04-13 14:29:34Z

0

NodeJS is not ES6. Set "type": "module" in the package.json as shown in the following image

answered Apr 13, 2023 at 14:29

Michele Delle Donne

2112 silver badges7 bronze badges

Collectives™ on Stack Overflow

Export-import in JavaScript --- SyntaxError: Cannot use import statement outside a module

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related