NodeJS “Must use import to load ES Module”

问题

I'm trying to import myArr from hello.js into index.js. However I get an error of

Error [ERR_REQUIRE_ESM]: Must use import to load ES Module

hello.js

export let myArr = ['hello', 'hi', 'hey'];

index.js

import { myArr } from './hello.js'
console.log(myArr)

Where am I going wrong?

回答1:

The problem is that node does not currently support import and export natively yet. It is still experimental according to the docs. I recommend you use babel to compile your code and allow you to use import and export.

For example, you can install the @babel/node package and run your project using:

npx babel-node index.js

Here are the docs for @babel/node. Like the docs state, this command is only meant for local development. In production, they recommend a configuration like this. Happy coding!

回答2:

I ran your code with no problem. Check for 2 things:

1. Node version >= 14. It only works with latest version of node.
2. Make sure your package.json includes a line for "type": "module", Without this line node assumes you want to use Common JS modules rather than ESM.

回答3:

you should use

module.exports.myArr = ['hello', 'hi', 'hey'];

as your export statement

edit: and use

const {myArr} = require('./hello.js')

as an import

来源：https://stackoverflow.com/questions/61670459/nodejs-must-use-import-to-load-es-module