Node module export/import && JS export/import with default and named

Bump

The module.exports or exports is a special object which is included in every JS file in the Node.js application by default. module is a variable that represents current module and exports is an object that will be exposed as a module. So, whatever you assign to module.exports or exports, will be exposed as a module.

var msg = require('./Messages.js');

console.log(msg);

JS export

The export statement is used when creating JavaScript modules to export functions, objects, or primitive values from the module so they can be used by other programs with the import statement.

There are two types of exports:

Named Exports (Zero or more exports per module)
Default Exports (One per module)


// file test.js
let k; export default k = 12;

// some other file
import m from './test'; // note that we have the freedom to use import m instead of import k, because k was default export
console.log(m);        // will log 12

// In childModule1.js
let myFunction = ...; // assign something useful to myFunction
let myVariable = ...; // assign something useful to myVariable
export {myFunction, myVariable};

// In childModule2.js
let myClass = ...; // assign something useful to myClass
export myClass;

// In parentModule.js
// Only aggregating the exports from childModule1 and childModule2
// to re-export them
export { myFunction, myVariable } from 'childModule1.js';
export { myClass } from 'childModule2.js';

// In top-level module
// We can consume the exports from a single module since parentModule
// "collected"/"bundled" them in a single source
import { myFunction, myVariable, myClass } from 'parentModule.js'

https://developer.mozilla.org/en-US/docs/web/javascript/reference/statements/export

https://www.tutorialsteacher.com/nodejs/nodejs-module-exports