CODEWITHSUNDEEP
javascriptnode.jswebmodule
mjquito
mjquito

Reputation: 582

In Node.js, why are variables equal the same across modules using the require function?

I have the following files in the same directory:

data.js

var anArray = [1,2];
module.exports = anArray;

mod1.js

var data = require('./data');
module.exports = data;

mod2.js

var data = require('./data');
module.exports = data;

main.js

var mod1 = require('./mod1');
var mod2 = require('./mod2');

When I do mod1 === mod2 it is true Why is that? My initial belief was that mod1 and mod2 files should contain an array but that are different (different references to the array objects).

Upvotes: 0

Views: 51

Answers (1)

dzm
dzm

Reputation: 23544

This is because modules are cached. Since you're referencing the same module twice, the second one is returning the exact same as the first. In your example, it's the same as doing the following:

const arr1 = [1,2]
const arr2 = [1,2]

arr1 === arr1 // true
arr1 === arr2 // false

The last line is false because you're comparing two different arrays.

Upvotes: 1

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