Javascript modules - Cannot use import statement outside a module

Question

I am new to Javascript and I am trying to learn modules from a tutorial. In have a folder in visual studio code/VScode which has two files, script.js & external.js.

Script.js imports content from external.js and prints text to console. I get the below error when I run script.js from vs code, with node.js run configuration. Can someone please tell me why this happens and how to fix it ? In comparison, imports in Java are simple.

import {keyValue} from './external.js';
^^^^^^

SyntaxError: Cannot use import statement outside a module
    at wrapSafe (internal/modules/cjs/loader.js:1070:16)
    at Module._compile (internal/modules/cjs/loader.js:1120:27)

external.js :

export let keyValue = 1000;

script.js :

import {keyValue} from './external.js';
console.log(keyValue);

UPDATES : Node version - v12.16.2, upgraded to v14.4.0.

your external.js file needs to be inside the root/modules folder — Ahmed Khattab
– Ahmed Khattab, Commented Jun 18, 2020 at 6:29
you need to tell node that you are using esm and not cjs. Either package.json: type: module or name your files with ext .mjs or use esm node -r esm script.js — grodzi
– grodzi, Commented Jun 18, 2020 at 6:32

mikemaccana · Accepted Answer · 2022-11-02 18:25:10Z

5

What's the version of node.js?

If node.js is version 13 or above, you can do either:

add { type: "module" } to package.json.

{
  ...
  scripts: "...",
  type: "module"
}

rename .js to .mjs

If it's under 13, rename `.js` to `.mjs`, and run with additional params `--experimental-modules`.

node --experimental-modules script.js

Or

You can also fix the import statement outside a module issue

by not using the import statement and using the dynamic import function instead.

script.js

import("./external.js").then((module) => {
    console.log(module.keyValue);
});

This form also supports the await keyword.

 let module = await import('./external.js');
 console.log(module.keyValue)

edited Nov 2, 2022 at 18:25

mikemaccana

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answered Jun 18, 2020 at 6:35

SPG

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3 Comments

MasterJoe Over a year ago

I upgraded it to v14.4.0. My tutorial does not mention package.json, but i setup one with npm init now. I am trying to understand how to make external.js a module which script.js can use.

SPG Over a year ago

@MasterJoe2 To make external.js as a module, you need to export it. and in ur script.js, import it. you can start from here, tutorialsteacher.com/nodejs/nodejs-module-exports

SPG Over a year ago

or u can update your post, including all files and file structures.

Minor Vargas · Accepted Answer · 2020-07-01 15:38:38Z

-1

it's because you are using es6 modules instead of the default module system for node which is common js. you could either use babel to transpile it or to use the .mjs extension

answered Jul 1, 2020 at 15:38

Minor Vargas

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Javascript modules - Cannot use import statement outside a module

2 Answers 2

What's the version of node.js?

If node.js is version 13 or above, you can do either:

If it's under 13, rename `.js` to `.mjs`, and run with additional params `--experimental-modules`.

Or

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2 Answers 2

What's the version of node.js?

If node.js is version 13 or above, you can do either:

If it's under 13, rename .js to .mjs, and run with additional params --experimental-modules.

Or

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If it's under 13, rename `.js` to `.mjs`, and run with additional params `--experimental-modules`.