CODEWITHSUNDEEP
node.jsexpress
vantage5353
vantage5353

Reputation: 565

Node: import object array from another js file?

In a file called data.js, I have a big object array:

var arr = [ {prop1: value, prop2: value},...]

I'd like to use this array into my Node.js app, but code like

require('./data.js')

doesn't help. I know how to export functions, but I'm lost when it comes to "importing" arrays. How do I add the data.js file to my app.js?

Upvotes: 22

Views: 71808

Answers (6)

Mudasir Habib
Mudasir Habib

Reputation: 848

data.js

 var arr = [ {prop1: value, prop2: value}]
 module.exports = { arr }

node.js

const {arr} = require('./data')
console.log(arr)

simple!

Upvotes: 0

Ashkon
Ashkon

Reputation: 21

We can use destructuring to solve your problem.

In file1.js, we create an object array:

var arr = [{ prop1: "beep", prop2: "boop" }];

Then we do the following to export:

module.exports = { arr };

Then in another file, file2.js, we require the array from file1

const f1 = require("./file1");

Log the result to test

console.log(f1.arr);

Upvotes: 2

HynekS
HynekS

Reputation: 3307

You can simply wrap your array in a function.

// myArray.js
export default function iDoReturnAnArray() {
  return ['foo', 'bar', 'baz'];
}

// main.js 
import iDoReturnAnArray from './path/to/myArray';

const unwrappedArray = iDoReturnAnArray();

console.log(unwrappedArray); // ['foo', 'bar', 'baz']

Upvotes: 3

Harshit Anand
Harshit Anand

Reputation: 702

You can directly get JSON or JSON array from any file in NODEJS there is no need to export it from a JS script

    [ {
        prop1: value, 
        prop2: value
      },
      {
        prop1: val,
        prop2: val2
      },
      ...
   ]

Store it to a JSON file suppose test.json

Now you can export it as given below its very simple.

let data = require('./test.json');

Upvotes: 6

muffel
muffel

Reputation: 7360

Local variables (var whatever) are not exported and local to the module. You can define your array on the exports object in order to allow to import it. You could create a .json file as well, if your array only contains simple objects.

data.js:

module.exports = ['foo','bar',3];

import.js

console.log(require('./data')); //output: [ 'foo', 'bar', 3 ]

[Edit]

If you require a module (for the first time), its code is executed and the exports object is returned and cached. For all further calls to require(), only the cached context is returned.

You can nevertheless modify objects from within a modules code. Consider this module:

module.exports.arr = [];
module.exports.push2arr = function(val){module.exports.arr.push(val);};

and calling code:

var mod = require("./mymodule");
mod.push2arr(2);
mod.push2arr(3);
console.log(mod.arr); //output: [2,3]

Upvotes: 37

Jonathan Lonowski
Jonathan Lonowski

Reputation: 123453

I know how to export functions, [...]

An array, or really any value, can be exported the same as functions, by modifying module.exports or exports:

var arr = [ {prop1: value, prop2: value},...];

exports.arr = arr;

var arr = require('./data').arr;

Upvotes: 6

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