导出函数 javascript 错误是什么意思，我该如何解决？

Question

so I'm trying to call the function jsonToAim(), which is created in a.js, in another script b.js

this is how I defined it in a.js:

export function jsonToAim(jsonObj){...}

this is how I called it in b.js

const backend = require('./a')`
let aimObj = backend.jsonToAim(jsonObj);

I ended up getting this error:

export function jsonToAim(jsonObj){
^^^^^^

SyntaxError: Unexpected token 'export'
    at wrapSafe (internal/modules/cjs/loader.js:992:16)
    at Module._compile (internal/modules/cjs/loader.js:1040:27)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1097:10)
    at Module.load (internal/modules/cjs/loader.js:941:32)
    at Function.Module._load (internal/modules/cjs/loader.js:782:14)
    at Module.require (internal/modules/cjs/loader.js:965:19)
    at require (internal/modules/cjs/helpers.js:88:18)
    at Object.<anonymous> (/create-aims/getAim.js:4:17)
    at Module._compile (internal/modules/cjs/loader.js:1076:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1097:10)

does anyone know where I went wrong? sorry if this is a stupid question i'm super new to js

Answer 1

There are multiple ways to export stuff in JS... eg, the CommonsJS vs ES6 export syntax.

NodeJS for whatever reason doesn't support at this time the ES6 import/export syntax you're employing.

Try the CommonJS syntax ( require/exports ):

const jsonToAim = (jsonObj) => {...}

//At the end of your file:
export {
 jsonToAim
}

Here's a really good thread about the ES6 vs CommonJS export syntax.

Answer 2

The problem is that you use ES Modules instead of CommonJS

Node.js uses by default Common js require()

That means that:

export function jsonToAim(jsonObj){...}

should be

function jsonToAim(jsonObj){...}

module.exports.jsonToAim = jsonToAim;

Later you import it with:

const { jsonToAim } = require(...);

However you can use ES modules in node.js too.

I have written an similar answer for this type of problem:

ES6 imports for JWT