Curly brackets (braces) in Node.js 'require' statement

Question

I am trying to understand the difference between the two \'require\' statements below.

Specifically, what is the purpose of the { }s wrapped around

Answer 1

With const electron = require('electron'), the ipcMain module will be available as electron.ipcMain.

With const {ipcMain} = require('electron') the ipcMain module will be available as ipcMain.

This construct is called object destructuring and achieves the same as the Python construct

from library import ...

In its basic form it allows you to refer to the properties of an object directly:

var o = {prop1: '1', prop2: 2}
var {prop1, prop2} = o
console.log(prop1) // '1' (same as o.prop1)
console.log(prop2) // 2 (same as o.prop2)

Check:

const {ipcMain} = require('electron')
const myElectron = require('electron')
const myipcMain = myElectron.ipcMain
console.log(myipcMain===ipcMain) // true

You can use the destructuring assignment to import multiple properties of a JavaScript object, e.g.:

const { app, BrowserWindow, ipcMain } = require('electron')

If you use a property that doesn't exist, this will be set to undefined and you won't get an error.

const {app, BrowserWindow, ipcMain, doesntExist} = require('electron')
console.log(doesntExist) // undefined

See also: What does curly brackets in the var { … } = … statements do?