Sharing & modifying a variable between multiple files node.js

Your problem is that when you do var count = require('./main.js').count;, you get a copy of that number, not a reference. Changing count does not change the "source".

However, you should have the files export functions. Requiring a file will only run it the first time, but after that it's cached and does not re-run. see docs

Suggestion #1:

// main.jsvar count = 1;var add = require('./add.js');count = add(count);// add.jsmodule.exports = function add(count) {    return count+10;}

#2:

var count = 1;var add = function() {    count += 10;}add();

#3: Personally i would create a counter module (this is a single instance, but you can easily make it a "class"):

// main.jsvar counter = require('./counter.js');counter.add();console.log(counter.count);// counter.jsvar Counter = module.exports = {    count: 1,    add: function() {        Counter.count += 10;    },    remove: function() {        Counter.count += 10;    }}

Not sure if this new or not but you can indeed share variables between files as such:

main.js

exports.main = {    facebook: null};

counter.js

var jamie = require('./main'); console.info(jamie); //{facebook: null}jamie.main.facebook = false;console.info(jamie); //{facebook: false}

anothercheck.js

var jamie = require('./main'); console.info(jamie); //{facebook: null} //values aren't updated when importing from the same file.jamie.main.facebook = true;console.info(jamie); //{facebook: true}

Now you can share between files.

I have same problem like you,.. Sometimes I'd like to sharing variables between multiple files because I love modular style eg. separating controller, function, models in different folders/files on my node.js script so I can easy manage the code.

I don't know if this is the best solution but I hope will suit your needs.

models/data.js

// exports empty arraymodule.exports = [];

controllers/somecontroller.js

var myVar = require('../models/data');myVar.push({name: 'Alex', age: 20});console.log(myVar);//  [{ name: 'Alex', age: 20 }]

controllers/anotherController.js

var myVar = require('../models/data');console.log(myVar);// This array has value set from somecontroller.js before...//  [{ name: 'Alex', age: 20 }]// Put new value to arraymyVar.push({name: 'John', age: 17});console.log(myVar);// Value will be added to an array//  [{ name: 'Alex', age: 20 }, { name: 'John', age: 17}]