How to access variable in another file in node js

Question

I have 2 files: export.js and server.js

I'm trying to access a variable in export.js in server.js, but I get undefined.

Note that I'm using knexjs and I gave it the name 'db';

export.js

let count;

const livePending = (db) => {
  db('cart')
  .count('id').where('status','=','Pending')
    .then(data => {
      if (data[0]) {
        count = data[0].count;
      }
    }).catch(err => res.status(400).send('DB Connection failed!'));
}

module.exports = {
    livePending: livePending,
    pCount: count
}

server.js

[...]
const anotherFile = require('./export');
anotherFile.livePending(db);
console.log(import.pCount);

When I try to console log inside the livePending function in export.js, I get the desired count which is 1.

The reason I'm doing this is to lessen the lines of code in my server.js. If I do the exact same function in my server.js, I get the correct result.

The exported variable in export.js seems to be named pCount, not count. Try console.log(import.pCount); instead. — remix23
– remix23, Commented Feb 14, 2019 at 11:34
Beside the fact that the varaible name is pCount as @remix23 said, 'import' is a reserved word in javascript so i think you should change the const name 'import' to something else then import — Wejd DAGHFOUS
– Wejd DAGHFOUS, Commented Feb 14, 2019 at 11:39

Andy Hoffman · Accepted Answer · 2021-08-29 17:48:31Z

3

I created a small node app to test a variation of your code. Two important findings:

1.

const import = require('./export');

import is reserved (as well as export). Node will throw a SyntaxError: Unexpected token if you attempt to use either one as a variable name.

2.

console.log(import.count);

In your code, you're attempting to log a variable that's already been returned. You'll notice the log statement will return undefined. Instead, create a function that you can call to get the value from the actual variable in the other file.

To make things clearer, here's a little demo to show these concepts in action.

export.js

let count;

const setCount = num => count = num;

const getCount = () => count;

// Shortcut: If the key: value is the same, we can just omit the value 
module.exports = {
  setCount,
  getCount
}

server.js

const ex = require('./export');
ex.setCount(5);
console.log(ex.getCount()); // 5

edited Aug 29, 2021 at 17:48

answered Feb 14, 2019 at 12:02

Andy Hoffman

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