Import function from another file in NodeJS without module

If you need to add an external function from other file into a nodejs file without changing the type into module type you can use this commonJS method

You can learn it ‘officialy’ about commonJS in Nodejs here in the official doc

How to export function from another file

Let’s say I have a function to return a random name on a helper function. I put it on ./src/utils/helper.js

function _getRandomName() {
    const randomName = Math.random().toString(36).substring(7) + '-' + Date.now()
    return randomName
}

// Important Part
module.exports = {
    _getRandomName
}

The very important part here is the module.exports where we list variable or function that we want to export to be used on other file

How to import function from another file

Not to use this function, let’s say on my server.js file that located in ./src/server.js is like this

const { _getRandomName } = require('./utils/helper')

Now you can use this helper function everywhere on server file

Add multiple functions ?

You can add the function name between the curly brackets, both, in the export and require part.